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/repo.go

@@ -173,7 +173,7 @@ type CreateRepoOption struct {
 type EditRepoOption struct {
 	// name of the repository
 	// unique: true
-	Name *string `json:"name,omitempty" binding:"OmitEmpty;AlphaDashDot;MaxSize(100);"`
+	Name *string `json:"name,omitempty" binding:"AlphaDashDot;MaxSize(100)"`
 	// a short description of the repository.
 	Description *string `json:"description,omitempty" binding:"MaxSize(2048)"`
 	// a URL with more information about the repository.