Usually, a client will only use text input v2/v3. Do not return the focused
surface for text input if it has no relevant text input resource.
If text-input object is created after surface get the focus, send
enter to this text input object. Ensure sendEnter and sendLeave always
appear in pair.
Also, use the same technique in text-input-v2 for text-input-v3 to
handle per resource's enable/disable state, and only send update to
enabled text-input-v3 object.
If we track the commit counts at compositor global, this will fail
horribly for anything other than the first text-input-v3 client, as for
new client the serial count will not be what it expects in the done()
request and it will simply consider events as outdated and will refuse
to accept those events
s_version is used only to initialize a global so there is no point for
storing protocol version in a static member field and use funky syntax
in the cpp file to initialize it. This change also simplifies the code.
