Custom reaction (#4517)

* Custom reaction

* increase limit of reactions/delete

* リアクションの場合は OS標準の絵文字を使用 を迂回する

* カスタムリアクションを無効にする設定

* fix

* disableCustomReaction --> enableEmojiReaction

* Avoid MFM rendering

* 🎨

* 🎨

* Auto accept

* custom emoji reaction

* Improve usability

* Extract emojiRegex

* Fix

* Clean up

* 🎨

* 🎨

* toDbReaction で reaction は必須に

あとフォールバックは like に

* Clean up

* Make required

* https://github.com/syuilo/misskey/pull/4517/commits/3eb08748feeaab9ee5c5b505c870f97d7edbeb0d#r266241728

* Refactor

* Allow null

src/server/api/endpoints/notes/reactions/create.ts

@@ -1,7 +1,6 @@
 import $ from 'cafy';
 import ID, { transform } from '../../../../../misc/cafy-id';
 import createReaction from '../../../../../services/note/reaction/create';
-import { validateReaction } from '../../../../../models/note-reaction';
 import define from '../../../define';
 import { getNote } from '../../../common/getters';
 import { ApiError } from '../../../error';
@@ -30,7 +29,7 @@ export const meta = {
 		},
 
 		reaction: {
-			validator: $.str.pipe(validateReaction.ok),
+			validator: $.str,
 			desc: {
 				'ja-JP': 'リアクションの種類'
 			}