Map OIDC groups to Orgs/Teams (#21441)

Fixes #19555

Test-Instructions:
https://github.com/go-gitea/gitea/pull/21441#issuecomment-1419438000

This PR implements the mapping of user groups provided by OIDC providers
to orgs teams in Gitea. The main part is a refactoring of the existing
LDAP code to make it usable from different providers.

Refactorings:
- Moved the router auth code from module to service because of import
cycles
- Changed some model methods to take a `Context` parameter
- Moved the mapping code from LDAP to a common location

I've tested it with Keycloak but other providers should work too. The
JSON mapping format is the same as for LDAP.


![grafik](https://user-images.githubusercontent.com/1666336/195634392-3fc540fc-b229-4649-99ac-91ae8e19df2d.png)

---------

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

routers/api/v1/repo/fork.go

@@ -108,7 +108,7 @@ func CreateFork(ctx *context.APIContext) {
 	if form.Organization == nil {
 		forker = ctx.Doer
 	} else {
-		org, err := organization.GetOrgByName(*form.Organization)
+		org, err := organization.GetOrgByName(ctx, *form.Organization)
 		if err != nil {
 			if organization.IsErrOrgNotExist(err) {
 				ctx.Error(http.StatusUnprocessableEntity, "", err)

routers/api/v1/repo/repo.go

@@ -468,7 +468,7 @@ func CreateOrgRepo(ctx *context.APIContext) {
 	//   "403":
 	//     "$ref": "#/responses/forbidden"
 	opt := web.GetForm(ctx).(*api.CreateRepoOption)
-	org, err := organization.GetOrgByName(ctx.Params(":org"))
+	org, err := organization.GetOrgByName(ctx, ctx.Params(":org"))
 	if err != nil {
 		if organization.IsErrOrgNotExist(err) {
 			ctx.Error(http.StatusUnprocessableEntity, "", err)