Add MangaMonk, Remove TrueManga

[vetleledaal]

Closes #3094

MangaMonk isn't a direct replacement, so I'm not reusing the same package name. Users would have to migrate from TrueManga to MangaMonk.

Checklist:

• [x] Updated extVersionCode value in build.gradle for individual extensions
• [x] Updated overrideVersionCode or baseVersionCode as needed for all multisrc extensions
• [x] Referenced all related issues in the PR body (e.g. "Closes #xyz")
• [x] Added the isNsfw = true flag in build.gradle when appropriate
• [ ] Have not changed source names
• [ ] Have explicitly kept the id if a source's name or language were changed
• [x] Have tested the modifications by compiling and running the extension through Android Studio
• [x] Have removed web_hi_res_512.png when adding a new extension