fix(frontend): MkCustomEmojiでフォールバックをテキストか画像か選べるように

fix of #13487

packages/frontend/src/components/global/MkCustomEmoji.vue

@@ -5,11 +5,12 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 <template>
 <img
-	v-if="errored"
+	v-if="errored && fallbackToImage"
 	:class="[$style.root, { [$style.normal]: normal, [$style.noStyle]: noStyle }]"
 	src="/client-assets/dummy.png"
 	:title="alt"
 />
+<span v-else-if="errored">:{{ customEmojiName }}:</span>
 <img
 	v-else
 	:class="[$style.root, { [$style.normal]: normal, [$style.noStyle]: noStyle }]"
@@ -44,6 +45,7 @@ const props = defineProps<{
 	useOriginalSize?: boolean;
 	menu?: boolean;
 	menuReaction?: boolean;
+	fallbackToImage?: boolean;
 }>();
 
 const react = inject<((name: string) => void) | null>('react', null);