Custom emoji & Sticker support (#686)

* Remove comments

* Show custom emoji first in suggestions

* Show global image packs in emoji picker

* Display emoji and sticker in room settings

* Fix some pack not visible in emojiboard

* WIP

* Add/delete/rename images to exisitng packs

* Change pack avatar, name & attribution

* Add checkbox to make pack global

* Bug fix

* Create or delete pack

* Add personal emoji in settings

* Show global pack selector in settings

* Show space emoji in emojiboard

* Send custom emoji reaction as mxc

* Render stickers as stickers

* Fix sticker jump bug

* Fix reaction width

* Fix stretched custom emoji

* Fix sending space emoji in message

* Remove unnessesary comments

* Send user pills

* Fix pill generating regex

* Add support for sending stickers

src/app/molecules/room-emojis/RoomEmojis.scss

@@ -0,0 +1,29 @@
+.room-emojis {
+  .image-pack,
+  .room-emojis__add-pack,
+  .room-emojis__empty {
+    margin: var(--sp-normal) 0;
+    background-color: var(--bg-surface);
+    border-radius: var(--bo-radius);
+    box-shadow: var(--bs-surface-border);
+    overflow: hidden;
+  
+    & > .context-menu__header:first-child {
+      margin-top: 2px;
+    }
+  }
+  &__add-pack {
+    & form {
+      margin: var(--sp-normal);
+      display: flex;
+      gap: var(--sp-normal);
+      & .input-container {
+        flex-grow: 1;
+      }
+    }
+  }
+  &__empty {
+    padding: var(--sp-extra-loose) var(--sp-normal);
+    text-align: center;
+  }
+}