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/structured_view.h

@@ -49,7 +49,7 @@ BACNET_STACK_EXPORT
 bool Structured_View_Object_Name(
     uint32_t object_instance, BACNET_CHARACTER_STRING *object_name);
 BACNET_STACK_EXPORT
-bool Structured_View_Name_Set(uint32_t object_instance, char *new_name);
+bool Structured_View_Name_Set(uint32_t object_instance, const char *new_name);
 BACNET_STACK_EXPORT
 const char *Structured_View_Name_ASCII(uint32_t object_instance);
 
@@ -57,9 +57,9 @@ BACNET_STACK_EXPORT
 int Structured_View_Read_Property(BACNET_READ_PROPERTY_DATA *rpdata);
 
 BACNET_STACK_EXPORT
-char *Structured_View_Description(uint32_t object_instance);
+const char *Structured_View_Description(uint32_t object_instance);
 BACNET_STACK_EXPORT
-bool Structured_View_Description_Set(uint32_t object_instance, char *new_name);
+bool Structured_View_Description_Set(uint32_t object_instance, const char *new_name);
 
 BACNET_STACK_EXPORT
 BACNET_NODE_TYPE Structured_View_Node_Type(uint32_t object_instance);
@@ -68,9 +68,9 @@ bool Structured_View_Node_Type_Set(
     uint32_t object_instance, BACNET_NODE_TYPE node_type);
 
 BACNET_STACK_EXPORT
-char *Structured_View_Node_Subtype(uint32_t object_instance);
+const char *Structured_View_Node_Subtype(uint32_t object_instance);
 BACNET_STACK_EXPORT
-bool Structured_View_Node_Subtype_Set(uint32_t object_instance, char *new_name);
+bool Structured_View_Node_Subtype_Set(uint32_t object_instance, const char *new_name);
 
 BACNET_STACK_EXPORT
 BACNET_SUBORDINATE_DATA *
@@ -110,7 +110,8 @@ BACNET_DEVICE_OBJECT_REFERENCE *
 Structured_View_Represents(uint32_t object_instance);
 BACNET_STACK_EXPORT
 bool Structured_View_Represents_Set(
-    uint32_t object_instance, BACNET_DEVICE_OBJECT_REFERENCE *represents);
+    uint32_t object_instance,
+    const BACNET_DEVICE_OBJECT_REFERENCE *represents);
 
 BACNET_STACK_EXPORT
 uint32_t Structured_View_Create(uint32_t object_instance);