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>

ports/arduino_uno/bip.h

@@ -28,11 +28,11 @@ extern "C" {
     /* on Linux, ifname is eth0, ath0, arc0, and others.
        on Windows, ifname is the dotted ip address of the interface */
     bool bip_init(char *ifname);
-    void bip_set_interface(char *ifname);
+    void bip_set_interface(const char *ifname);
     void bip_cleanup(void);
 
     /* Convert uint8_t IPv4 to uint32 */
-    uint32_t convertBIP_Address2uint32(uint8_t * bip_address);
+    uint32_t convertBIP_Address2uint32(const uint8_t * bip_address);
     void convertUint32Address_2_uint8Address(uint32_t ip,
         uint8_t * address);
     /* common BACnet/IP functions */
@@ -68,12 +68,12 @@ extern "C" {
     uint16_t bip_get_port(void);
 
     /* use network byte order for setting */
-    void bip_set_addr(uint8_t * net_address);
+    void bip_set_addr(const uint8_t * net_address);
     /* returns network byte order */
     uint8_t *bip_get_addr(void);
 
     /* use network byte order for setting */
-    void bip_set_broadcast_addr(uint8_t * net_address);
+    void bip_set_broadcast_addr(const uint8_t * net_address);
     /* returns network byte order */
     uint8_t *bip_get_broadcast_addr(void);