fix problems with requesting AT; add usage count check

internal/db/dbModels/supertoken.go

internal/endpoints/token/access/accessTokenEndpoint.go

internal/endpoints/token/super/pkg/authCodeFlowRequest.go

internal/oidc/authcode/authcode.go

internal/supertoken/restrictions/restriction.go

internal/supertoken/restrictions/restriction_test.go

internal/utils/hashUtils/hashUtils.go

internal/utils/hashUtils/hashUtils_test.go