refactor: move go-chi/binding into Gitea (#39528)

The `gitea.com/go-chi/binding` package only exists for Gitea, so it
moves into `modules/web/binding` to fix its bugs directly. Split out of
https://github.com/go-gitea/gitea/pull/39504.

- GET and HEAD always bind the query
- JSON `null` slice elements and nested `TrimSpace` fields bind
correctly
- Integer fields reject out-of-range values instead of wrapping
- An empty JSON body binds nothing and an unknown binding rule is an
error

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: bircni <bircni@icloud.com>

modules/structs/org_team.go

@@ -63,7 +63,7 @@ type CreateTeamOption struct {
 	// Whether the team can create repositories in the organization
 	CanCreateOrgRepo bool `json:"can_create_org_repo"`
 	// Team visibility within the organization. Defaults to "private".
-	Visibility TeamVisibility `json:"visibility" binding:"OmitEmpty;In(public,limited,private)"`
+	Visibility TeamVisibility `json:"visibility" binding:"In(public,limited,private)"`
 }
 
 // EditTeamOption options for editing a team
@@ -85,5 +85,5 @@ type EditTeamOption struct {
 	CanCreateOrgRepo *bool `json:"can_create_org_repo"`
 	// Team visibility within the organization. When omitted, visibility is
 	// left unchanged.
-	Visibility *TeamVisibility `json:"visibility" binding:"OmitEmpty;In(public,limited,private)"`
+	Visibility *TeamVisibility `json:"visibility" binding:"In(public,limited,private)"`
 }