feat: add support to define custom oidc scopes

[sydefz]

Allow customisation on oidc scopes, users can now use druid.auth.oidc.customScopes=["scope_name"] to define a list of scopes to request from idp. The implementation also ensures a default openid scope is always included.

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[van-vothanh]

@sydefz how are you going to define the custom oidc scopes? We'd probably want to expose this as a cdk.json property so we could keep track of all the changes in cdk/cloudformation

[sydefz]

@van-vothanh I have added the ability define custom oidc scopes in cdk.json under oidcIdpConfig.

And the following cases are tested:

1. not setting oidcIdpConfig.customScopes, oidc extension will use default email+profile+openid scopes
2. setting oidcIdpConfig.customScopes=[new_scope], oidc extension will add openid scope to remain compliant to the oidc spec, the request will have new_scope+openid scopes
3. setting oidcIdpConfig.customScopes=[new_scope, other_scope], oidc extension will add openid scope to remain compliant to the oidc spec, the request will have new_scope+openid scopes
4. setting oidcIdpConfig.customScopes=[new_scope, openid], oidc extension will use new_scope+openid scopes