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/device.c

@@ -574,7 +574,7 @@ bool Device_Objects_Property_List_Member(
 static uint32_t Object_Instance_Number = 260001;
 static BACNET_CHARACTER_STRING My_Object_Name;
 static BACNET_DEVICE_STATUS System_Status = STATUS_OPERATIONAL;
-static char *Vendor_Name = BACNET_VENDOR_NAME;
+static const char *Vendor_Name = BACNET_VENDOR_NAME;
 static uint16_t Vendor_Identifier = BACNET_VENDOR_ID;
 static char Model_Name[MAX_DEV_MOD_LEN + 1] = "GNU";
 static char Application_Software_Version[MAX_DEV_VER_LEN + 1] = "1.0";
@@ -783,7 +783,7 @@ bool Device_Object_Name(
     return status;
 }
 
-bool Device_Set_Object_Name(BACNET_CHARACTER_STRING *object_name)
+bool Device_Set_Object_Name(const BACNET_CHARACTER_STRING *object_name)
 {
     bool status = false; /*return value */
 
@@ -1124,7 +1124,7 @@ int Device_Object_List_Element_Encode(
  * Object.
  * @return True on success or else False if not found.
  */
-bool Device_Valid_Object_Name(BACNET_CHARACTER_STRING *object_name1,
+bool Device_Valid_Object_Name(const BACNET_CHARACTER_STRING *object_name1,
     BACNET_OBJECT_TYPE *object_type,
     uint32_t *object_instance)
 {
@@ -1519,7 +1519,7 @@ int Device_Read_Property_Local(BACNET_READ_PROPERTY_DATA *rpdata)
  * @return The length of the APDU on success, else BACNET_STATUS_ERROR
  */
 static int Read_Property_Common(
-    struct object_functions *pObject, BACNET_READ_PROPERTY_DATA *rpdata)
+    const struct object_functions *pObject, BACNET_READ_PROPERTY_DATA *rpdata)
 {
     int apdu_len = BACNET_STATUS_ERROR;
     BACNET_CHARACTER_STRING char_string;
@@ -1852,7 +1852,7 @@ static bool Device_Write_Property_Object_Name(
     BACNET_OBJECT_TYPE object_type = OBJECT_NONE;
     uint32_t object_instance = 0;
     int apdu_size = 0;
-    uint8_t *apdu = NULL;
+    const uint8_t *apdu = NULL;
 
     if (!wp_data) {
         return false;