Added scope copy for authorization_code and refresh_token grants.

[PetrasJaug]

PR Checklist

• I have run npm test locally and all tests are passing.
• I have added/updated tests for any new behavior.
• If this is a significant change, an issue has already been created where the problem / solution was discussed: why scope set to dummy for authorization_code and refresh_token #259

PR Description

Takes scope from request if available and uses 'dummy' if not. Fixes issue where MSAL library invalidates cache if scope is not matching and therefore requests a new token on every request.

[PetrasJaug]

@poveden This could break flows where scope was provided and the consumer still relied on receiving 'dummy'. Could be under an args feature flag if this breaks too much.