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>

integrations/org_count_test.go

@@ -9,7 +9,7 @@ import (
 	"strings"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/organization"
 	"code.gitea.io/gitea/models/unittest"
 	user_model "code.gitea.io/gitea/models/user"
 	api "code.gitea.io/gitea/modules/structs"
@@ -117,7 +117,7 @@ func doCheckOrgCounts(username string, orgCounts map[string]int, strict bool, ca
 			Name: username,
 		}).(*user_model.User)
 
-		orgs, err := models.FindOrgs(models.FindOrgOptions{
+		orgs, err := organization.FindOrgs(organization.FindOrgOptions{
 			UserID:         user.ID,
 			IncludePrivate: true,
 		})