go back to form after submitting an edit form

- rename image fields on podcast, episode and persons for better clarity
- set different sizes
config for podcast cover, banner and persons avatars
- add tiny size for covers
- fix responsive
on admin forms

- create Admin, Analytics, Auth, Fediverse and Install modules in the root modules/ folder
- rename
ActivityPub to Fediverse

- use default avatar image if person image is not set
- add thumbnail and medium default avatar
images
- set default avatar images directly in public/media folder
- remove public/media's root
folder from .gitignore
- remove unnecessary copy:images script and cpy-cli package

closes #125

fix some style issues

fix episode, podcast and persons forms + episode scheduling