Add branch_filter to hooks API endpoints (#26599)

We now include the branch filler in the response.

- Closes #26591 

# Before

![image](73933940-c1a7-4573-abae-f340b63028b2)

# After

![image](3b3c4a85-0f7c-48c7-8617-def7a66c671d)

---------

Signed-off-by: Yarden Shoham <git@yardenshoham.com>
Co-authored-by: Giteabot <teabot@gitea.io>

modules/structs/hook.go

@@ -19,6 +19,7 @@ var ErrInvalidReceiveHook = errors.New("Invalid JSON payload received over webho
 type Hook struct {
 	ID                  int64             `json:"id"`
 	Type                string            `json:"type"`
+	BranchFilter        string            `json:"branch_filter"`
 	URL                 string            `json:"-"`
 	Config              map[string]string `json:"config"`
 	Events              []string          `json:"events"`