Enhance(frontend): MFMや絵文字が使える入力ボックスでオートコンプリートを使えるように (#12643)

* rich autocomplete for use in profiles, announcements, and channel descriptions

* implementation omissions

* add tab, apply to page editor, and fix something

* componentization

* fix nyaize doesn't working in profile preview

* detach autocomplete instance when unmounted

* fix: mismatched camelCase

* remove unused / unnecessary styles

* update CHANGELOG.md

* fix lint

* remove dump.rdb

* props.richAutocomplete -> autocomplete

* Update packages/frontend/src/scripts/autocomplete.ts

* clarify namings
メンションなども「MFM」に含まれるのか自信がなかったのでrichSyntaxなどとぼかしていましたが、含むようなので変更しました

* tweak

* Update MkFormDialog.vue

* rename

---------

Co-authored-by: syuilo <Syuilotan@yahoo.co.jp>

packages/frontend/src/pages/admin/announcements.vue

@@ -25,7 +25,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 					<MkInput v-model="announcement.title">
 						<template #label>{{ i18n.ts.title }}</template>
 					</MkInput>
-					<MkTextarea v-model="announcement.text">
+					<MkTextarea v-model="announcement.text" mfmAutocomplete :mfmPreview="true">
 						<template #label>{{ i18n.ts.text }}</template>
 					</MkTextarea>
 					<MkInput v-model="announcement.imageUrl" type="url">
@@ -75,7 +75,6 @@ import { ref, computed } from 'vue';
 import XHeader from './_header_.vue';
 import MkButton from '@/components/MkButton.vue';
 import MkInput from '@/components/MkInput.vue';
-import MkTextarea from '@/components/MkTextarea.vue';
 import MkSwitch from '@/components/MkSwitch.vue';
 import MkRadios from '@/components/MkRadios.vue';
 import MkInfo from '@/components/MkInfo.vue';
@@ -83,6 +82,7 @@ import * as os from '@/os.js';
 import { i18n } from '@/i18n.js';
 import { definePageMetadata } from '@/scripts/page-metadata.js';
 import MkFolder from '@/components/MkFolder.vue';
+import MkTextarea from '@/components/MkTextarea.vue';
 
 const announcements = ref<any[]>([]);