[xasiat] add support (#4161 #5929 #7934)

* [xasiat] Album extractor
* [xasiat] Tags, categories, Models
* [xasiat] Tests
* update 'album' extractor
    - provide 'album_id' metadata
    - use redirected 'album_url' value
    - update metadata extraction in general
* extend test result data

docs/supportedsites.md

@@ -1175,6 +1175,12 @@ Consider all listed sites to potentially be NSFW.
     <td>Galleries</td>
     <td></td>
 </tr>
+<tr>
+    <td>Xasiat</td>
+    <td>https://www.xasiat.com</td>
+    <td>Albums, Categories, Models, Tag Searches</td>
+    <td></td>
+</tr>
 <tr>
     <td>Xfolio</td>
     <td>https://xfolio.jp/</td>