Rename legacy PleromaFE Chat functionality to "Shout"

src/App.js

src/App.vue

src/boot/after_store.js

src/boot/routes.js

src/components/features_panel/features_panel.js

src/components/features_panel/features_panel.vue

src/components/shout_panel/shout_panel.js

src/components/shout_panel/shout_panel.vue

src/components/side_drawer/side_drawer.js

src/main.js

src/modules/api.js

src/modules/instance.js

src/modules/shout.js

src/modules/users.js

static/config.json