Tag aliases (#1412)

* Add Tag Update/UpdateFull
* Tag alias implementation
* Refactor tag page
* Add aliases in UI
* Include tag aliases in q filter
* Include aliases in tag select
* Add aliases to auto-tagger
* Use aliases in scraper
* Add tag aliases for filename parser

pkg/database/migrations/24_tag_aliases.up.sql

@@ -0,0 +1,7 @@
+CREATE TABLE `tag_aliases` (
+  `tag_id` integer,
+  `alias` varchar(255) NOT NULL,
+  foreign key(`tag_id`) references `tags`(`id`) on delete CASCADE
+);
+
+CREATE UNIQUE INDEX `tag_aliases_alias_unique` on `tag_aliases` (`alias`);