Implement RFC 8628

[nsklikas]

BREAKING CHANGES: This patch breaks up `OAuth2AuthorizeExplicitFactory` into
`OAuth2AuthorizeExplicitAuthFactory` and `Oauth2AuthorizeExplicitTokenFactory`

Related Design Document

Implements RFC 8628.

Checklist

• [x] I have read the contributing guidelines and signed the CLA.
• [x] I have referenced an issue containing the design document if my change introduces a new feature.
• [x] I have read the security policy.
• [x] I confirm that this pull request does not address a security vulnerability. If this pull request addresses a security vulnerability, I confirm that I got approval (please contact security@ory.sh) from the maintainers to push the changes.
• [x] I have added tests that prove my fix is effective or that my feature works.
• [x] I have added the necessary documentation within the code base (if appropriate).

Further comments

This PR is based on the work done on https://github.com/ory/fosite/pull/701, by @supercairos and @BuzzBumbleBee. That PR was based on an older version of fosite and was missing some features/tests.

Comments:

• Due to some dependency issues we had to switch to go.uber.org/mock/gomock (github.com/golang/mock/gomock is deprecated)
• We had to do a small refactor of the AuthorizeExplicitGrantHandler to generalize it to reduce code duplication

[CLAassistant]

All committers have signed the CLA.

[nsklikas]

Looks like the conformity tests are failing because it tries to use this version of fosite on hydra master. But they pass on the hydra PR with this version of fosite. Changes are needed on the hydra config DefaultProvider object, how should we fix this?

[aeneasr]

Looks like the conformity tests are failing because it tries to use this version of fosite on hydra master. But they pass on the hydra PR with this version of fosite. Changes are needed on the hydra config DefaultProvider object, how should we fix this?

You should be able to change the target commit in the CI file to target your PR in hydra, which should make the tests pass

[nsklikas]

Thank you for the reviews.

I reverted the refactor on the oauth2 handlers and tried to address all the comments. Also pinned the ci to use hydra from the PR branch and now the tests pass. Please have another go.