tag releases with recording title instead of tracklist title

### Proposed solution

Plugin or config option to allow tagging of full releases with (more "canonical") recording title instead of tracklist title.

### Objective

Tracklist titles are often different (or wrong/unclear!) between different releases, while recording titles are converged and more "canonical."

#### Goals

Greater convergence of titles for the same song.

No files or tests are named. Start by locating the release-tagging path and the plugin/configuration mechanisms, then determine how tracklist and recording titles are selected. Done should include an opt-in way to tag full releases with recording titles while preserving existing behavior.

Written by the indexing model from the issue text.