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/zephyr/bip-init.c

@@ -150,7 +150,7 @@ void bip_get_broadcast_address(BACNET_ADDRESS *dest)
  * @param addr - network IPv4 address
  * @return true if the address was set
  */
-bool bip_set_addr(BACNET_IP_ADDRESS *addr)
+bool bip_set_addr(const BACNET_IP_ADDRESS *addr)
 {
     if (addr) {
         memcpy(&BIP_Address.s_addr, &addr->address[0], IP_ADDRESS_MAX);
@@ -180,7 +180,7 @@ bool bip_get_addr(BACNET_IP_ADDRESS *addr)
  * @param addr - network IPv4 address
  * @return true if the address was set
  */
-bool bip_set_broadcast_addr(BACNET_IP_ADDRESS *addr)
+bool bip_set_broadcast_addr(const BACNET_IP_ADDRESS *addr)
 {
     if (addr) {
         memcpy(&BIP_Broadcast_Addr.s_addr, &addr->address[0], IP_ADDRESS_MAX);
@@ -249,7 +249,8 @@ uint8_t bip_get_subnet_prefix(void)
  * @return Upon successful completion, returns the number of bytes sent.
  *  Otherwise, -1 shall be returned and errno set to indicate the error.
  */
-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)
 {
     struct sockaddr_in bip_dest = { 0 };
 
@@ -267,7 +268,7 @@ int bip_send_mpdu(BACNET_IP_ADDRESS *dest, uint8_t *mtu, uint16_t mtu_len)
     /* Send the packet */
     debug_print_ipv4(
         "Sending MPDU->", &bip_dest.sin_addr, bip_dest.sin_port, mtu_len);
-    return zsock_sendto(BIP_Socket, (char *)mtu, mtu_len, 0,
+    return zsock_sendto(BIP_Socket, (const char *)mtu, mtu_len, 0,
         (struct sockaddr *)&bip_dest, sizeof(struct sockaddr));
 }
 
@@ -404,7 +405,7 @@ int bip_send_pdu(BACNET_ADDRESS *dest,
  * @param ifname [in] The named interface to use for the network layer.
  *        Eg, for Linux, ifname is eth0, ath0, arc0, and others.
  */
-void bip_set_interface(char *ifname)
+void bip_set_interface(const char *ifname)
 {
     struct net_if *iface = 0;
     int index = -1;
@@ -492,7 +493,7 @@ void bip_set_interface(char *ifname)
     }
 }
 
-static int createSocket(struct sockaddr_in *sin)
+static int createSocket(const struct sockaddr_in *sin)
 {
     int sock_fd = -1;
     const int sockopt = 1;