Remove deprecated Manga constructors

[palaks-1]

Remove deprecated Manga constructors to make sure authors field is propagated and author is derived from it

[Koitharu]

I believe it would be better to store authors as Set<String>:

• If source require some id of author we should find it by name (like it implemented in MangaDex now)
• User can provide author name directly
• Author does not depends on source

[palaks-1]

I believe it would be better to store authors as Set<String>:

• If source require some id of author we should find it by name (like it implemented in MangaDex now)
• User can provide author name directly
• Author does not depends on source

@Koitharu not all sources have same capabilities like MangaDex to get id by name for example MangaNato where we can get authors manga with this path /author/story/fHxjaGluYV9yZWFkaW5n and there is no way to get id by name there but we can get it during details retrieval for manga and i believe there is quite a lot of such sources.
Yes they can pass author as a name in search filed but it will treated as a search query in Kotatsu app from my understanding and if we would have separate field to search by author then it can put empty key to it.
With MangaTag for author we will be able to get more sources to work with author search or we can have AuthorTag without source field in it (not sure how this source is used)
What do you think?

[Koitharu]

I would like to merge this feature into master before Kotatsu v8 release so let's keep it string for a while

[palaks-1]

I would like to merge this feature into master before Kotatsu v8 release so let's keep it string for a while

Ok then will rebase it to master and use Set<String>

[Koitharu]

Don't rebase and don't worry about conflicts, I'll fix it when merge

I believe most manga sources provide some way to obtain author id by name. In all we need an ability to search by author string for global search across multiple sources

[palaks-1]

Don't rebase and don't worry about conflicts, I'll fix it when merge

I believe most manga sources provide some way to obtain author id by name. In all we need an ability to search by author string for global search across multiple sources

I already rebased))
It was needed because originally this MR was raised into feature/search_query and based on feature/search_query so if you want to merge it in master it should have to be rebased to master
Otherwise it will bring feature/search_query commits to master and it didn't have your today Manga constractor refactoring a0168a7