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/schedule.c

@@ -459,7 +459,8 @@ bool Schedule_Write_Property(BACNET_WRITE_PROPERTY_DATA *wp_data)
  * @param date - date to check
  * @return true if the calendar entry is within the effective period
  */
-bool Schedule_In_Effective_Period(SCHEDULE_DESCR *desc, BACNET_DATE *date)
+bool Schedule_In_Effective_Period(
+    const SCHEDULE_DESCR *desc, const BACNET_DATE *date)
 {
     bool res = false;
 
@@ -480,7 +481,7 @@ bool Schedule_In_Effective_Period(SCHEDULE_DESCR *desc, BACNET_DATE *date)
  * @param time - time of the day
  */
 void Schedule_Recalculate_PV(
-    SCHEDULE_DESCR *desc, BACNET_WEEKDAY wday, BACNET_TIME *time)
+    SCHEDULE_DESCR *desc, BACNET_WEEKDAY wday, const BACNET_TIME *time)
 {
     int i;
     desc->Present_Value.tag = BACNET_APPLICATION_TAG_NULL;