Introduce pluginKey

Summary: Exposed the `pluginKey` to sandy plugins (which we will use later for storing table preferences per plugin). And a little moving code around because circular deps problem roared its ugly head again.

Reviewed By: nikoant

Differential Revision: D27009721

fbshipit-source-id: 7ad29e72ff8028c9daae270c4749b657bd8ff049

desktop/app/src/utils/pluginUtils.tsx

@@ -12,7 +12,6 @@ import {
   FlipperBasePlugin,
   PluginDefinition,
   DevicePluginDefinition,
-  isSandyPlugin,
   ClientPluginDefinition,
 } from '../plugin';
 import type {State} from '../reducers';
@@ -54,6 +53,12 @@ export function getPluginKey(
   return `unknown#${pluginID}`;
 }
 
+export function isSandyPlugin(
+  plugin?: PluginDefinition | null,
+): plugin is _SandyPluginDefinition {
+  return plugin instanceof _SandyPluginDefinition;
+}
+
 export function getPersistedState<PersistedState>(
   pluginKey: string,
   persistingPlugin: typeof FlipperBasePlugin | null,