Remove SVG icons from emoji picker and using font icons

packages/rocketchat-emojione/category_icons/activity.svg

packages/rocketchat-emojione/category_icons/flags.svg

packages/rocketchat-emojione/category_icons/foods.svg

packages/rocketchat-emojione/category_icons/nature.svg

packages/rocketchat-emojione/category_icons/objects.svg

packages/rocketchat-emojione/category_icons/people.svg

packages/rocketchat-emojione/category_icons/recent.svg

packages/rocketchat-emojione/category_icons/symbols.svg

packages/rocketchat-emojione/category_icons/travel.svg

packages/rocketchat-emojione/emojiPicker.html

packages/rocketchat-emojione/emojiPicker.less

packages/rocketchat-emojione/package.js

packages/rocketchat-ui-message/message/messageBox.html