Refactor radio title parsing

[hasezoey]

This PR changes the radio title parsing to be its own function and overwrite the full string instead of appending, in more details:

• dont append new title to old
• move parsing to own function for better code clarity and direct testing
• parse until '; instead of just ' (for things like Don't)
• add tests for the parsing

Now instead of Currently Playing: Artist - Some Title - Artist - Some other Title - Artist - Some other other Title it will only display Currently Playing: Artist - Some other other Title

also somehow before this PR sometimes the string would just go blank and never recover for reasons unknown to me, but now it seemingly does not anymore