Make all api fields snake_case (#105)

Change all snake/camelCase mix and match to camelCase everywhere

Fix conversion to not interfer with service interceptors

Add dynamic conversion between camelCase and snake_case to services

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/frontend/pulls/105

src/models/teamMember.js

@@ -7,7 +7,7 @@ export default class TeamMemberModel extends UserModel {
 			super.defaults(),
 			{
 				admin: false,
-				teamID: 0,
+				teamId: 0,
 			}
 		)
 	}