feat: introduce new front-end UI button for cross-posting, hide move on topics in remote cids

- Hide the ability to select remote cids in topic move category search
- Add a new option to category search: 'localOnly'; pretty self descriptive.

src/api/search.js

@@ -66,6 +66,7 @@ async function findMatchedCids(uid, data) {
 		query: data.search,
 		qs: data.query,
 		paginate: false,
+		localOnly: data.localOnly,
 	});
 
 	let matchedCids = result.categories.map(c => c.cid);