feat: add prefix winresizer to plugin messages

[uwla]

The prefix can be used to filter out the messages (for example, make Noice hide them).

[simeji]

Thank you for the contribution! Adding a prefix to plugin messages is a great idea for compatibility with plugins like Noice.

One concern: the mode status line is shortened to [winresizer] mode resize, which removes the key hints ("Enter": OK, "e": Change mode, "q": Cancel). These are valuable for discoverability, especially for new users. Would you be open to keeping the key hints while adding the prefix? Something like:

[winresizer] resize mode ... "Enter": OK , "e": Change mode , "q": Cancel