Add tag input component

app/components/commander/action_buttons.hbs

app/components/commander/context_menu/index.hbs

app/components/commander/context_menu/index.js

app/components/commander/index.hbs

app/components/commander/index.js

app/components/modal/tags.hbs

app/components/modal/tags.js

app/components/tag_input/index.hbs

app/components/tag_input/index.js

app/components/tag_input/item.hbs

app/components/tag_input/item.js

app/styles/app.scss

app/styles/components/tag_input.scss