[SDK-3589] Improve defaultOptions management (#952)
[SDK-3589] Improve defaultOptions management (#952)

Co-authored-by: Frederik Prijck <1419d4624e69b96dea8d827a60b0dcef2149eecf@auth0.com>
auth0/auth0-spa-js,auth0/auth0-spa-js,auth0/auth0-spa-js