Move organization related structs into sub package (#18518)

* Move organization related structs into sub package

* Fix test

* Fix lint

* Move more functions into sub packages

* Fix bug

* Fix test

* Update models/organization/team_repo.go

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>

* Apply suggestions from code review

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>

* Fix fmt

* Follow suggestion from @Gusted

* Fix test

* Fix test

* Fix bug

* Use ctx but db.DefaultContext on routers

* Fix bug

* Fix bug

* fix bug

* Update models/organization/team_user.go

* Fix bug

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

models/main_test.go

@@ -7,6 +7,7 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/organization"
 	repo_model "code.gitea.io/gitea/models/repo"
 	"code.gitea.io/gitea/models/unittest"
 	user_model "code.gitea.io/gitea/models/user"
@@ -30,7 +31,7 @@ func TestFixturesAreConsistent(t *testing.T) {
 		&PullRequest{},
 		&Milestone{},
 		&Label{},
-		&Team{},
+		&organization.Team{},
 		&Action{})
 }