System-wide webhooks (#10546)

* Create system webhook column (and migration)

* Create system webhook DB methods

Based on the default webhook ones

* Modify router to handle system webhooks and default ones

* Remove old unused admin nav template

* Adjust orgRepoCtx to differentiate system and default webhook URLs

* Assign IsSystemWebhook when creating webhooks

* Correctly use booleans for IsSystemWebhook

* Use system webhooks when preparing webhooks for payload

* Add UI and locale changes

* Use router params to differentiate admin hook pages

* Fix deleting admin webhooks and rename method

* Add clarity to webhook docs

* Revert "Remove old unused admin nav template"

This reverts commit 191a20a738.

* Rename WebHooksNewPost to GiteaHooksNewPost for clarity

* Reintroduce blank line lost during merge conflict

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Lauris BH <lauris@nix.lv>

modules/webhook/webhook.go

@@ -181,6 +181,13 @@ func prepareWebhooks(repo *models.Repository, event models.HookEventType, p api.
 		ws = append(ws, orgHooks...)
 	}
 
+	// Add any admin-defined system webhooks
+	systemHooks, err := models.GetSystemWebhooks()
+	if err != nil {
+		return fmt.Errorf("GetSystemWebhooks: %v", err)
+	}
+	ws = append(ws, systemHooks...)
+
 	if len(ws) == 0 {
 		return nil
 	}