Add voice information to lyrics

[michilyy]

What kind of change does this PR introduce? (check at least one)

• [ ] Bugfix
• [x] Feature
• [ ] Code style update
• [ ] Refactor
• [ ] Build-related changes
• [ ] Other, please describe:

The PR fulfills these requirements:

• [ ] When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx[,#xxx], where "xxx" is the issue number)

If adding a new feature, the PR's description includes:

• [x] A convincing reason for adding this feature (it's best to open a suggestion issue first and wait for approval before working on it)

Other information: Provide voice information in lyrics lines. Detailed features listen in #188

Synced lyrics are now checked for voice information. The behavior is described in #188

The lyrics request now contains a colour key: