It shouldn't happen that we get the presence stanza without a resource.
https://datatracker.ietf.org/doc/html/rfc6120
```
Implementation Note: It is the server's responsibility to deliver
only stanzas that are addressed to the client's full JID or the
user's bare JID; thus, there is no need for the client to check
the 'to' address of incoming stanzas. However, if the client does
check the 'to' address then it is suggested to check at most the
bare JID portion (not the full JID), since the 'to' address might
be the user's bare JID, the client's current full JID, or even a
full JID with a different resourcepart (e.g., in the case of so-
called "offline messages" as described in [XEP-0160]).
```
Let's not segfault though.
Close https://github.com/profanity-im/profanity/issues/1630
create_unique_id() was changed to use UUIDs instead of a counter in the
last commit. Since now it depends on connection_create_uuid() which is
in the xmpp subfolder the function should also be moved there.
Renamed it to connection_create_stanza_id() and moved it to
src/xmpp/connection.c.
Discussion happened in https://github.com/boothj5/profanity/pull/1010
In most get-like funcitons libstrophe returns pointer to a string
that resides in an internal structure (e.g. xmpp_stanza_t). Hence,
Profanity must not change such strings. Define respective variables
as 'const char*' to reduce a chance of error and conform future
libstrophe's interface.
This patch mostly replaces 'char *' with 'const char*', but also
fixes two memory leaks after stanza_get_reason(). Add comment within
stanza_get_reason() to fix conflict with different allocator types.
