[arcalive] add support (#5657 #7100)

* [arca.live] Add extractor skeleton

* [arcalive] update names and formatting

* [arcalive] implement initial file extraction code

* [arcalive] improve '_extract_media()' performance

compile and cache regex on demand

* [arcalive] improve image extraction

- extract 'data-originalurl' URLs if available
- replace URL query strings with 'type=orig'
- ignore emoticons by default

* [arcalive] update defaults

- include 'title' in filenames
- use 0.5-1.5s delay between requests

* [arcalive] use ext from 'data-orig' if available

* [arcalive] update docs/supportedsites

* [arcalive] add tests

* [arcalive] update 'board' extractor pattern

so it doesn't also match 'post' URLs

---------

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

docs/configuration.rst

@@ -384,6 +384,7 @@ Type
 Default
     * ``"0.5-1.5"``
         ``ao3``,
+        ``arcalive``,
         ``civitai``,
         ``[Danbooru]``,
         ``[E621]``,
@@ -1394,6 +1395,16 @@ Description
     Format(s) to download.
 
 
+extractor.arcalive.emoticons
+----------------------------
+Type
+    ``bool``
+Default
+    ``false``
+Description
+    Download emoticon images.
+
+
 extractor.artstation.external
 -----------------------------
 Type