Refactor approval URL construction in access and secret approval request services

- Updated the construction of approval URLs to use a consistent project path format.
- Modified notification payloads to include the new approval URL structure.
- Enhanced Slack message formatting to include buttons for viewing requests directly.

backend/src/lib/workflow-integrations/types.ts

@@ -21,6 +21,7 @@ export type TNotification =
         requestId: string;
         projectId: string;
         secretKeys: string[];
+        approvalUrl: string;
       };
     }
   | {
@@ -52,6 +53,7 @@ export type TNotification =
         editNote?: string;
         editorFullName?: string;
         editorEmail?: string;
+        projectPath: string;
       };
     }
   | {