Pre-installs and registers kqlmagic (#9558)

Co-authored-by: Monica Gupta <mogupt@microsoft.com>

extensions/notebook/src/jupyter/jupyterSessionManager.ts

@@ -350,6 +350,10 @@ export class JupyterSession implements nb.ISession {
 					allCode += `%set_env ${key}=${process.env[key]}${EOL}`;
 				}
 			}
+
+			// Add and register Kqlmagic to the python kernel
+			allCode += `%reload_ext Kqlmagic`;
+
 			let future = this.sessionImpl.kernel.requestExecute({
 				code: allCode,
 				silent: true,