Support to upgrade local chart app deployment

**Problem:**
Cannot upgrade app with local template files

**Solution:**
Add `Files` field to `AppUpgradeConfig`

**Issue:**
https://github.com/rancher/rancher/issues/15711

apis/project.cattle.io/v3/app_types.go

@@ -81,6 +81,7 @@ type AppUpgradeConfig struct {
 	ExternalID   string            `json:"externalId,omitempty"`
 	Answers      map[string]string `json:"answers,omitempty"`
 	ForceUpgrade bool              `json:"forceUpgrade,omitempty"`
+	Files        map[string]string `json:"files,omitempty"`
 }
 
 type RollbackRevision struct {