Make most of functions const correct (#714)

* Make most of the functions const correct

Used clang-tidy and sonarlint to help find places where const could
pretty easily applied. Also lot of hand work.

This commit does not yet touch handlers and typedefs of those.

* Fix Arduino uno handler_who_is() has extra parenthesis

For some reason there is extra parenthesis. Remove it this is more
likely buildable.

* Bugfix/bacapp: Fix uninitilized array_index

We have changed bacapp_snprintf_value() to be const correct. After that
we got

```
/home/runner/work/bacnet-stack/bacnet-stack/src/bacnet/bacapp.c:3183:27: warning: 4th function call argument is an uninitialized value [core.CallAndMessage]
                ret_val = bacapp_snprintf_weeklyschedule(
                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 warning generated.
```

So analyzer could now spot that we do not actually initilize array_index
at all. Fix this by setting array_index to zero. Note that I actually do
not know if zeroing is right thing to do here. I choose zero as if this
has worked before it is most likely that it will work with zero value.

* cmake: Add and ignore Wwrite-strings compiler option

Wwrite-strings helps find places where const correctness is broken.

Example it will warn about these

```C

void func1(char* str);

func("test") /* "test" is const so we should not pass it to func1().

char* func2()
{
  return "test"; /* func2() should return const char*.
}
```

We still need to ignore it as not all are fixed but let's add it already
so we remember that it should be opened at some point.

---------

Co-authored-by: Kari Argillander <kari.argillander@fidelix.com>

src/bacnet/basic/object/lo.c

@@ -198,7 +198,8 @@ unsigned Lighting_Output_Instance_To_Index(uint32_t object_instance)
  * @return the priority-array active status for the specific priority
  */
 static bool
-Priority_Array_Active(struct object_data *pObject, BACNET_ARRAY_INDEX priority)
+Priority_Array_Active(
+    const struct object_data *pObject, BACNET_ARRAY_INDEX priority)
 {
     bool active = false;
 
@@ -219,7 +220,8 @@ Priority_Array_Active(struct object_data *pObject, BACNET_ARRAY_INDEX priority)
  * @return The priority-array value for the specific priority
  */
 static float
-Priority_Array_Value(struct object_data *pObject, BACNET_ARRAY_INDEX priority)
+Priority_Array_Value(
+    const struct object_data *pObject, BACNET_ARRAY_INDEX priority)
 {
     float real_value = 0.0;
 
@@ -241,7 +243,7 @@ Priority_Array_Value(struct object_data *pObject, BACNET_ARRAY_INDEX priority)
  * @return The priority-array value for the specific priority
  */
 static float Priority_Array_Next_Value(
-    struct object_data *pObject, BACNET_ARRAY_INDEX priority)
+    const struct object_data *pObject, BACNET_ARRAY_INDEX priority)
 {
     float real_value = 0.0;
     unsigned p = 0;
@@ -316,7 +318,7 @@ static int Lighting_Output_Priority_Array_Encode(
  *
  * @return  active priority 1..16, or 0 if no priority is active
  */
-static unsigned Present_Value_Priority(struct object_data *pObject)
+static unsigned Present_Value_Priority(const struct object_data *pObject)
 {
     unsigned p = 0; /* loop counter */
     unsigned priority = 0; /* return value */
@@ -837,7 +839,7 @@ bool Lighting_Output_Object_Name(
  *
  * @return  true if object-name was set
  */
-bool Lighting_Output_Name_Set(uint32_t object_instance, char *new_name)
+bool Lighting_Output_Name_Set(uint32_t object_instance, const char *new_name)
 {
     bool status = false; /* return value */
     struct object_data *pObject;
@@ -876,15 +878,15 @@ const char *Lighting_Output_Name_ASCII(uint32_t object_instance)
  *
  * @return description text or NULL if not found
  */
-char *Lighting_Output_Description(uint32_t object_instance)
+const char *Lighting_Output_Description(uint32_t object_instance)
 {
-    char *name = NULL;
-    struct object_data *pObject;
+    const char *name = NULL;
+    const struct object_data *pObject;
 
     pObject = Keylist_Data(Object_List, object_instance);
     if (pObject) {
         if (pObject->Description) {
-            name = (char *)pObject->Description;
+            name = pObject->Description;
         } else {
             name = "";
         }
@@ -901,7 +903,8 @@ char *Lighting_Output_Description(uint32_t object_instance)
  *
  * @return  true if object-name was set
  */
-bool Lighting_Output_Description_Set(uint32_t object_instance, char *new_name)
+bool Lighting_Output_Description_Set(
+    uint32_t object_instance, const char *new_name)
 {
     bool status = false; /* return value */
     struct object_data *pObject;
@@ -924,7 +927,7 @@ bool Lighting_Output_Description_Set(uint32_t object_instance, char *new_name)
  * @return  true if lighting command was set
  */
 bool Lighting_Output_Lighting_Command_Set(
-    uint32_t object_instance, BACNET_LIGHTING_COMMAND *value)
+    uint32_t object_instance, const BACNET_LIGHTING_COMMAND *value)
 {
     bool status = false;
     struct object_data *pObject;
@@ -970,7 +973,7 @@ Lighting_Command_Stop(struct object_data *pObject, unsigned priority)
  */
 static bool Lighting_Output_Lighting_Command_Write(
     uint32_t object_instance,
-    BACNET_LIGHTING_COMMAND *value,
+    const BACNET_LIGHTING_COMMAND *value,
     uint8_t priority,
     BACNET_ERROR_CLASS *error_class,
     BACNET_ERROR_CODE *error_code)
@@ -1858,7 +1861,7 @@ bool Lighting_Output_Color_Reference(
  * @return  true if property value was set
  */
 bool Lighting_Output_Color_Reference_Set(
-    uint32_t object_instance, BACNET_OBJECT_ID *value)
+    uint32_t object_instance, const BACNET_OBJECT_ID *value)
 {
     bool status = false;
     struct object_data *pObject;
@@ -1922,7 +1925,7 @@ bool Lighting_Output_Override_Color_Reference(
  * @return  true if property value was set
  */
 bool Lighting_Output_Override_Color_Reference_Set(
-    uint32_t object_instance, BACNET_OBJECT_ID *value)
+    uint32_t object_instance, const BACNET_OBJECT_ID *value)
 {
     bool status = false;
     struct object_data *pObject;