[iwara] Add support (#2652 #5840 #7785)

* [iwara] Add initial support
* [iwara] Add search support
* [iwara] Code cleanup
* [iwara] Small fixes and additions
* [iwara] Add tag support
* [iwara] Add mime-type to metadata
* [iwara] Refactor patterns/matching using urllib
* [iwara] Add unit tests
* [iwara] Update docs
* [iwara] Fix linting on older Python versions
* [iwara] update 'IwaraAPI' interface class
    - define endpoints inside methods
    - implement and use _call() and _pagination()
    - cache auth tokens
* [iwara] split and rename 'profile' extractor
    TODO:
    - update test results
    - simplify code
* [iwara] simplify '_user_params()' usage
* [iwara] update 'video' extractor
    and move user data extraction into 'yield_video'
* [iwara] update 'image' extractor
    and move user info extraction into 'yield_image()'
* [iwara] update 'playlist' extractor
* [iwara] update 'search' extractor
* [iwara] update 'tag' extractor
* [iwara] simplify 'yield_image' usage
    perform API calls to get full 'files' list inside the function
* [iwara] add video "image" test
* [iwara] provide 'date' metadata
* [iwara] simplify 'source()'
    remove urllib.parse usage
* [iwara] small optimizations
    * get("key", {}) -> get("key") or {}
    * split("…", 1) -> partition("…")
    * use f-strings for all patterns
* [iwara] add missing 'keyarg=1' to profile() memcache decorator
* [tests/iwara] update results
* [iwara] extract more 'user' metadata
* [iwara] update default format strings
    include 'date' in filenames to order them chronologically
* [iwara] restructure image/video handling
    - use less generators
    - make processing individual media items non-fatal
* [iwara] fix login and token handling
* [iwara] add 'favorite' extractor
* [iwara] add 'following' and 'followers' extractors

---------

Co-authored-by: Mike Fährmann <mike_faehrmann@web.de>

scripts/supportedsites.py

@@ -287,6 +287,11 @@ SUBCATEGORY_MAP = {
         "saved": "Saved Posts",
         "tagged": "Tagged Posts",
     },
+    "iwara": {
+        "user-images": "User Images",
+        "user-videos": "User Videos",
+        "user-playlists": "User Playlists",
+    },
     "kemono": {
         "discord"       : "Discord Servers",
         "discord-server": "",
@@ -475,6 +480,7 @@ AUTH_MAP = {
     "imgbb"          : "Supported",
     "inkbunny"       : "Supported",
     "instagram"      : _COOKIES,
+    "iwara"          : "Supported",
     "kemono"         : "Supported",
     "mangadex"       : "Supported",
     "mangoxo"        : "Supported",