[Session] Base (#3541)

* Add readLastActiveAccount to use accounts[] as source of truth

* Add public service constant, use

src/state/session/util/readLastActiveAccount.ts

@@ -0,0 +1,6 @@
+import * as persisted from '#/state/persisted'
+
+export function readLastActiveAccount() {
+  const {currentAccount, accounts} = persisted.get('session')
+  return accounts.find(a => a.did === currentAccount?.did)
+}