Merge branch 'fixes-roundup4' into 'develop'

build/dev-server.js

changelog.d/roundup4.skip

package.json

src/App.scss

src/components/attachment/attachment.style.js

src/components/attachment/attachment.vue

src/components/button_unstyled.style.js

src/components/chat/chat.vue

src/components/chat_list_item/chat_list_item.vue

src/components/chat_message/chat_message.vue

src/components/chat_new/chat_new.vue

src/components/checkbox/checkbox.vue

src/components/confirm_modal/confirm_modal.js

src/components/confirm_modal/confirm_modal.vue

src/components/emoji_reactions/emoji_reactions.scss

src/components/emoji_reactions/emoji_reactions.vue

src/components/mention_link/mention_link.js

src/components/mention_link/mention_link.vue

...ts/mobile_post_status_button/mobile_post_status_button.js

...ponents/mrf_transparency_panel/mrf_transparency_panel.vue