Support custom short code stickers

Issue #105.

src/components/messages/MessageOutgoingSticker.vue

@@ -0,0 +1,47 @@
+<template>
+  <div class="messageOut">
+    <div class="op-button" ref="opbutton">
+      <v-btn icon @click.stop="showContextMenu($refs.opbutton)"
+        ><v-icon>more_vert</v-icon></v-btn
+      >
+    </div>
+    <div class="bubble sticker-bubble">
+      <v-img :aspect-ratio="16 / 9" ref="image" :src="src" :cover="cover" :contain="contain" />
+      <QuickReactions :event="event" :reactions="reactions" />
+    </div>
+    <v-avatar class="avatar" size="32" color="#ededed" @click.stop="ownAvatarClicked">
+      <img v-if="userAvatar" :src="userAvatar" />
+      <span v-else class="white--text headline">{{ userAvatarLetter }}</span>
+    </v-avatar>
+    <div class="senderAndTime">
+      <!-- <div class="sender">{{ "You" }}</div> -->
+      <div class="time">
+        {{ formatTime(event.event.origin_server_ts) }}
+        <div class="status">{{ event.status }}</div>
+      </div>
+    </div>
+  </div>
+</template>
+
+<script>
+import messageMixin from "./messageMixin";
+import stickers from "../../plugins/stickers";
+
+export default {
+  mixins: [messageMixin],
+  data() {
+    return {
+      src: null,
+      cover: false,
+      contain: true,
+    };
+  },
+  mounted() {
+    this.src = stickers.getStickerImage(this.event.getContent().body)
+  },
+};
+</script>
+
+<style lang="scss">
+@import "@/assets/css/chat.scss";
+</style>