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>

test/bacnet/datalink/mock/src/bip-mock.c

@@ -19,7 +19,7 @@ bool bip_init(char *ifname)
     return ztest_get_return_value();
 }
 
-void bip_set_interface(char *ifname)
+void bip_set_interface(const char *ifname)
 {
     ztest_check_expected_value(ifname);
 }
@@ -56,7 +56,8 @@ int bip_send_pdu(
     return ztest_get_return_value();
 }
 
-int bip_send_mpdu(BACNET_IP_ADDRESS *dest, uint8_t *mtu, uint16_t mtu_len)
+int bip_send_mpdu(
+    const BACNET_IP_ADDRESS *dest, const uint8_t *mtu, uint16_t mtu_len)
 {
     ztest_check_expected_value(dest);
     ztest_check_expected_data(mtu, mtu_len);
@@ -87,7 +88,7 @@ uint16_t bip_get_port(void)
     return ztest_get_return_value();
 }
 
-bool bip_set_addr(BACNET_IP_ADDRESS *addr)
+bool bip_set_addr(const BACNET_IP_ADDRESS *addr)
 {
     ztest_check_expected_data(addr, sizeof(BACNET_IP_ADDRESS));
     return ztest_get_return_value();
@@ -111,7 +112,7 @@ void bip_get_broadcast_address(BACNET_ADDRESS *dest)
     ztest_copy_return_data(dest, sizeof(BACNET_ADDRESS));
 }
 
-bool bip_set_broadcast_addr(BACNET_IP_ADDRESS *addr)
+bool bip_set_broadcast_addr(const BACNET_IP_ADDRESS *addr)
 {
     return ztest_get_return_value();
 }

test/bacnet/datalink/mock/src/bip6-mock.c

@@ -58,13 +58,13 @@ void bip6_set_interface(char *ifname)
     ztest_check_expected_value(ifname);
 }
 
-bool bip6_address_match_self(BACNET_IP6_ADDRESS *addr)
+bool bip6_address_match_self(const BACNET_IP6_ADDRESS *addr)
 {
     ztest_check_expected_value(addr);
     return ztest_get_return_value();
 }
 
-bool bip6_set_addr(BACNET_IP6_ADDRESS *addr)
+bool bip6_set_addr(const BACNET_IP6_ADDRESS *addr)
 {
     ztest_check_expected_data(addr, sizeof(BACNET_IP6_ADDRESS));
     return ztest_get_return_value();
@@ -91,12 +91,12 @@ void bip6_get_broadcast_address(BACNET_ADDRESS *my_address)
     ztest_copy_return_data(my_address, sizeof(BACNET_ADDRESS));
 }
 
-bool bip6_set_broadcast_addr(BACNET_IP6_ADDRESS *addr)
+bool bip6_set_broadcast_addr(const BACNET_IP6_ADDRESS *addr)
 {
     return ztest_get_return_value();
 }
 
-int bip6_send_mpdu(BACNET_IP6_ADDRESS *dest, uint8_t *mtu, uint16_t mtu_len)
+int bip6_send_mpdu(const BACNET_IP6_ADDRESS *dest, const uint8_t *mtu, uint16_t mtu_len)
 {
     ztest_check_expected_value(dest);
     ztest_check_expected_data(mtu, mtu_len);

test/bacnet/datalink/mock/src/ethernet-mock.c

@@ -45,7 +45,7 @@ uint16_t ethernet_receive(
     return ztest_get_return_value();
 }
 
-void ethernet_set_my_address(BACNET_ADDRESS *my_address)
+void ethernet_set_my_address(const BACNET_ADDRESS *my_address)
 {
     ztest_check_expected_data(my_address, sizeof(BACNET_ADDRESS));
 }
@@ -60,7 +60,7 @@ void ethernet_get_broadcast_address(BACNET_ADDRESS *dest)
     ztest_copy_return_data(dest, sizeof(BACNET_ADDRESS));
 }
 
-void ethernet_debug_address(const char *info, BACNET_ADDRESS *dest)
+void ethernet_debug_address(const char *info, const BACNET_ADDRESS *dest)
 {
     ztest_check_expected_value(info);
     ztest_check_expected_value(dest);