Drag to reorder/resize cameras in camera groups (#11279)

* draggable/resizable cameras in camera groups on desktop/tablets

* fix edit button location on tablets

* assume 1rem is 16px

web/src/hooks/use-persistence.ts

@@ -1,10 +1,11 @@
 import { useEffect, useState, useCallback } from "react";
-import { get as getData, set as setData } from "idb-keyval";
+import { get as getData, set as setData, del as delData } from "idb-keyval";
 
 type usePersistenceReturn<S> = [
   value: S | undefined,
   setValue: (value: S | undefined) => void,
   loaded: boolean,
+  deleteValue: () => void,
 ];
 
 export function usePersistence<S>(
@@ -26,6 +27,11 @@ export function usePersistence<S>(
     [key],
   );
 
+  const deleteValue = useCallback(async () => {
+    await delData(key);
+    setInternalValue(defaultValue);
+  }, [key, defaultValue]);
+
   useEffect(() => {
     setLoaded(false);
     setInternalValue(defaultValue);
@@ -41,5 +47,5 @@ export function usePersistence<S>(
     load();
   }, [key, defaultValue, setValue]);
 
-  return [value, setValue, loaded];
+  return [value, setValue, loaded, deleteValue];
 }