feat: fetch features and store locally for offline users (#706)

* feat: fetch features and store locally for offline users

* feat: handle success and error cases

* refactor: move offline activation code reading/validation to snjs

* chore: update after renaming snjs function

* fix: correct condition for checking offline users

* feat: let users remove their previous offline keys (WIP)

* refactor: handle setOfflineFeatures function response accordingly

* feat: remove corresponding local data when removing offline key

* fix: use snjs' confirm dialog instead of custom one

* feat: show warning before installing extension from untrusted source

* refactor: move functions for validating external feature url and checking if custom server host was used to snjs

* chore: put correct snjs version

* chore: make `eslint-plugin-react-hooks` in yarn.lock to match the `develop` branch

* chore: deps update

* chore: deps update

app/assets/javascripts/strings.ts

@@ -111,6 +111,9 @@ export const STRING_UPGRADE_ACCOUNT_CONFIRM_TEXT =
   '<a href="https://standardnotes.com/help/security" target="_blank">Security Upgrade page.</a>';
 export const STRING_UPGRADE_ACCOUNT_CONFIRM_BUTTON = 'Upgrade';
 
+export const STRING_REMOVE_OFFLINE_KEY_CONFIRMATION =
+  'This will delete the previously saved offline key.';
+
 export const Strings = {
   protectingNoteWithoutProtectionSources:
     'Access to this note will not be restricted until you set up a passcode or account.',