Add a simple way to rename branch like gh (#15870)

- Update default branch if needed
- Update protected branch if needed
- Update all not merged pull request base branch name
- Rename git branch
- Record this rename work and auto redirect for old branch on ui

Signed-off-by: a1012112796 <1012112796@qq.com>
Co-authored-by: delvh <dev.lh@web.de>

services/forms/repo_branch_form.go

@@ -24,3 +24,15 @@ func (f *NewBranchForm) Validate(req *http.Request, errs binding.Errors) binding
 	ctx := context.GetContext(req)
 	return middleware.Validate(errs, ctx.Data, f, ctx.Locale)
 }
+
+// RenameBranchForm form for rename a branch
+type RenameBranchForm struct {
+	From string `binding:"Required;MaxSize(100);GitRefName"`
+	To   string `binding:"Required;MaxSize(100);GitRefName"`
+}
+
+// Validate validates the fields
+func (f *RenameBranchForm) Validate(req *http.Request, errs binding.Errors) binding.Errors {
+	ctx := context.GetContext(req)
+	return middleware.Validate(errs, ctx.Data, f, ctx.Locale)
+}