feat: add podcast banner field for each podcast + refactor images configuration

- 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

app/Models/PersonModel.php

@@ -35,8 +35,8 @@ class PersonModel extends Model
         'full_name',
         'unique_name',
         'information_url',
-        'image_path',
-        'image_mimetype',
+        'avatar_path',
+        'avatar_mimetype',
         'created_by',
         'updated_by',
     ];