Replace all use of <a> + href='#' with proper buttons

src/App.scss

src/components/account_actions/account_actions.vue

...omponents/async_component_error/async_component_error.vue

src/components/attachment/attachment.js

src/components/attachment/attachment.vue

src/components/block_card/block_card.vue

src/components/chat_list/chat_list.vue

src/components/chat_message/chat_message.scss

src/components/chat_message/chat_message.vue

src/components/conversation/conversation.vue

src/components/desktop_nav/desktop_nav.scss

src/components/desktop_nav/desktop_nav.vue

src/components/domain_mute_card/domain_mute_card.vue

src/components/emoji_reactions/emoji_reactions.vue

src/components/export_import/export_import.vue

src/components/exporter/exporter.vue

src/components/extra_buttons/extra_buttons.vue

src/components/favorite_button/favorite_button.js

src/components/favorite_button/favorite_button.vue

src/components/follow_button/follow_button.vue