Optionally specify an encryption key when saving data to a local Realm

[kraenhansen]

Is your feature request related to a problem? Please describe.

When a user wants to ship an app with an encrypted Realm file containing data, it would be nice to be able to save data from the browser into a Realm file with encryption enabled. Currently only saving to a non-encrypted Realm file is possible.

Describe the solution you'd like

Add another option to the "File" → "Save data" menu labeled "Encrypted Local Realm" which would prompt the user to enter an encryption key.

Describe alternatives you've considered

Users can manually load the Realmfile into the Realm JS SDK and use the writeCopyTo API: https://realm.io/docs/javascript/latest/api/Realm.html#writeCopyTo

Additional context See a forum post from a user experiencing this need https://forum.realm.io/t/any-way-to-encrypt-realm-file-w-realm-studio/3242/3.