Add persistent state provider (#1830)

* Add persistent state provider

* Catch write error

* Handle read errors, update error msgs

* Fix lint

* Don't provide initial state to loader

* Remove colorMode from shell state

* Idea: hook into persisted context from other files

* Migrate settings to new hook

* Rework persisted state to split individual contexts

* Tweak persisted schema and validation

---------

Co-authored-by: Paul Frazee <pfrazee@gmail.com>

src/state/persisted/broadcast/index.ts

@@ -0,0 +1,6 @@
+export default class BroadcastChannel {
+  constructor(public name: string) {}
+  postMessage(_data: any) {}
+  close() {}
+  onmessage: (event: MessageEvent) => void = () => {}
+}