[FEATURE] Add an option to select a release group

[floriplum]

Is your feature request related to a problem? Please describe.
Currently it is not possible to select the release group that is downloaded. It would sometimes be helpful if i could select the release group.

Describe the solution you'd like
Add a flag that allows you to select the release group. For example --release-group "Groupxxx"

Describe alternatives you've considered
There currently is none that im aware of.

Additional context
None

[olofvndrhr]

Until now the release group was fixed to avoid an issue with external releases which were incompatible with the mangex api.
If you can provide an example for a manga with two different mangadex release groups (not external ones) i can look at it.

[floriplum]

One example is Berserk, there you have many Chapters with multiple release groups.
https://mangadex.org/title/801513ba-a712-498c-8f57-cae55b38cc92/berserk

It could also be helpful if you can set a priority for the release groups that you like, but that is a bit more complex : )