Light novel and manga with same names creating conflict

[Arima57]

With the increasing number of LN to manga adaptations and vice versa and Anilist APIs inherent inability to tell the two apart, the get_manga and get_manga_id methods seem to be having unexpected behaviors because of the collisions. For the time being, it can SORT of be fixed by a little bit of work and manual selection turned on but separating LN and Manga completely might be a bit tedious without disturbing the existing functionality.

[Arima57]

I'll create a pull request for now with the makeshift fix. (It simply adds a ' (lightnovel)' indicator at the end of lightnovel names during manual selection).

Additionally, I eliminated some boilerplate that was likely unnecessary.