feat: Detect DJ-mix based on the release title or track titles

[gustavkj]

Part of: #15

Adds support for detecting DJ-mixes by their titles and/or if the track titles end with (mixed) (in different formats).

Contrary to detection of Live releases, there are examples of DJ-mixes having multiple media one with the mixed tracks and one with the unmixed tracks. Some examples of this are the DJ-Kicks releases: DJ-Kicks: Modeselektor or DJ-Kicks: Disclosure.

When searching on Spotify, there were a few releases just called DJ mix which do not seem to be DJ-mixes per se. Also, considered Continuous Mix, but that seemed to also include just tracks with seamless transitions but not DJ-mixes really.

Some cases

• https://open.spotify.com/album/4VtQwmTZHlFxO6hw9hgu5J
• https://open.spotify.com/album/4ApWMQXAEOaNpFWaKG2FtN (first medium is DJ-mixed, second is the unmixed tracks. The release group should still be DJ-mix)
• https://open.spotify.com/album/0f1k2l7T0SDIuAGFoXVPnF (track names contain mixed and the release title ends with (DJ mix))
• https://open.spotify.com/album/1Ufqq0yg7gEyRQ70ofgKXe (release title ends with (Continuous DJ mix)
• https://open.spotify.com/album/3YCh0CPUNvjvnuaJ459MZv (release title ends with [DJ mix])
• https://music.apple.com/us/album/paragon-continuous-dj-mix-dj-mix/1755446194 (mixes [Mixed] and (Mixed) suffixes)
• https://open.spotify.com/album/5TaKyO5IvwE8nknuFmXpA4 (release title that just contains Continuous DJ mix)

False negative:

• https://open.spotify.com/album/3uA7wc39YN6UmondQbxDrh (Last track title ends with - Bonus track mixed).

[kellnerd]

Looks good to me, but I have to admit that I usually don't deal with DJ-mix releases.
I probably won't do a new release until Sunday at least, so I would appreciate other opinions/reviews.

[arsinclair]

so I would appreciate other opinions/reviews.

Sorry, I also saw this but I don't have a particular opinion on the matter. If there's not a lot of false-positives, then this change is useful :)