[Feature Request] Support search by id for register command

[nuxencs]

Currently only searching by manga name is supported like this:
mangathr register -s mangadex "Berserk"
It would be nice to be able to search by id in case of MangaDex being the source, as it would eliminate false positives:
mangathr register -s mangadex "801513ba-a712-498c-8f57-cae55b38cc92"

[browningluke]

Hey @nuxencs, thanks for opening this issue!

This will be added in the next minor release (later today / this week).