[SDK-3613] Remove defaultScope and replace with just scope usage

[ewanharris]

Changes

This PR removes the advancedOptions.defaultScope option in favour of authorizationParams.scope. This allows the SDK to have a single place to set scopes when instantiating a new Client (although additional scopes can still be provided to the getToken* methods).

For those who were already providing a scope option, it should be updated as follows.

const client = new Auth0Client({
  domain: '<AUTH0_DOMAIN>',
  clientId: '<AUTH0_CLIENT_ID>',
- authorizationParams: {
-   scope: 'read:messages'
- }
+ authorizationParams: {
+   scope: 'profile email read:messages'
+ }
});

For those who were using advancedOptions.defaultScope you should merge advancedOptions.defaultScope with authorizationParams.scope:

const client = new Auth0Client({
  domain: '<AUTH0_DOMAIN>',
  clientId: '<AUTH0_CLIENT_ID>',
- authorizationParams: {
-   scope: 'read:messages'
- }
- advancedOptions: {
-   defaultScope: 'email'
- }
+ authorizationParams: {
+   scope: 'email read:messages'
+ }
});

Checklist

• I have read the Auth0 general contribution guidelines
• I have read the Auth0 Code of Conduct
• All code quality tools/guidelines have been run/followed