Since BE doesn't support fetching user by screen name over MastoAPI we'll gonna

just fetching it over QvitterAPI real quick :DDDDDDDDD

src/services/backend_interactor_service/backend_interactor_service.js

@@ -26,6 +26,10 @@ const backendInteractorService = (credentials) => {
     return apiService.fetchAllFollowing({username, credentials})
   }
 
+  const figureOutUserId = ({screenName}) => {
+    return apiService.figureOutUserId({screenName, credentials})
+  }
+
   const fetchUser = ({id}) => {
     return apiService.fetchUser({id, credentials})
   }
@@ -95,6 +99,7 @@ const backendInteractorService = (credentials) => {
     unfollowUser,
     blockUser,
     unblockUser,
+    figureOutUserId,
     fetchUser,
     fetchUserRelationship,
     fetchAllFollowing,