Multiple verses handling

[bkunda]

In cases like the above, we'll need a system to automatically determine that:

• multiple verses have been consolidated into a single verse
• a single verse has to be expanded to multiple verses

and in such cases provide options for

• adding curly braces where appropriate
• (automatically) centering any relevant lyric extension lines vertically to the brace

This feature may need more fleshing out, but I'm placing it here so we have a clear record of what the minimum requirements are.

Stems from https://github.com/musescore/MuseScore/issues/30664