Unify analysis and tagged commands

[Splendide-Imaginarius]

Is your feature request related to a problem? Please describe.

Currently, deciding whether to use play or play-tagged requires knowing in advance whether the audio file has loop tags. split-audio and extend do not have any tagged equivalents at all.

Describe the solution you'd like

I suggest removing the play-tagged command, and making all commands that run loop analysis optionally (per a command-line flag) skip the analysis if loop tags are already present in the file. This would decrease code redundancy and make the UX substantially simpler.

The flag would have three possible values:

• Always run loop analysis, ignore tags.
• Always use tags, error if tags not present.
• (Default) use tags if present, run loop analysis otherwise.

Describe alternatives you've considered (if relevant)

Adding more commands for split-audio-tagged and extend-tagged could be done, but this would make the code a lot more unwieldy and redundant.

Additional context

I'd be happy to submit a PR if the concept is welcome.

[Splendide-Imaginarius]

(play-tagged also doesn't support loading from a URL, which would also be fixed by this.)