[FR] add API to get available reviewers & assignees

[noerw]

expose repo.GetReviewers() as GET /api/v1/repos/<owner>/<repo>/reviewers
expose repo.GetAssignees() as GET /api/v1/repos/<owner>/<repo>/assignees

gitea/models/repo.go

Lines 617 to 624 in a4148c0

	// GetReviewers get all users can be requested to review:
	// * for private repositories this returns all users that have read access or higher to the repository.
	// * for public repositories this returns all users that have read access or higher to the repository,
	// all repo watchers and all organization members.
	// TODO: may be we should have a busy choice for users to block review request to them.
	func (repo *Repository) GetReviewers(doerID, posterID int64) ([]*User, error) {
	return repo.getReviewers(x, doerID, posterID)
	}

This would be helpful for tea issue create

[6543]

blocking

• https://codeberg.org/gitnex/GitNex/issues/200
• https://gitea.com/noerw/tea/src/branch/issue-create-opts/modules/interact/issue_create.go#L118