[Glitch] Rewrite actions/modal and reducers/modal with typescript

Port 38c6216082 to glitch-soc

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/flavours/glitch/features/compose/containers/dropdown_container.js

@@ -7,7 +7,7 @@ import Dropdown from '../components/dropdown';
 
 const mapDispatchToProps = dispatch => ({
   isUserTouching,
-  onModalOpen: props => dispatch(openModal('ACTIONS', props)),
+  onModalOpen: props => dispatch(openModal({ modalType: 'ACTIONS', modalProps: props })),
   onModalClose: () => dispatch(closeModal()),
 });