Add telemetry when python terminal REPL is used

[karthiknadig]

Use Shell Integration to detect when python terminal REPL is used.

[anthonykim1]

Will attempt to use:

		 * Creates a stream of raw data (including escape sequences) that is written to the
		 * terminal. This will only include data that was written after `read` was called for
		 * the first time, ie. you must call `read` immediately after the command is executed via
		 * {@link TerminalShellIntegration.executeCommand} or
		 * {@link window.onDidStartTerminalShellExecution} to not miss any data.
		 *
		 * @example
		 * // Log all data written to the terminal for a command
		 * const command = term.shellIntegration.executeCommand({ commandLine: 'echo "Hello world"' });
		 * const stream = command.read();
		 * for await (const data of stream) {
		 *   console.log(data);
		 * }
		 */
		read(): AsyncIterable<string>;

from https://github.com/microsoft/vscode/blob/main/src/vscode-dts/vscode.proposed.terminalShellIntegration.d.ts
to read() right after executing Terminal REPL launch commands.

[anthonykim1]

Verification step:

1. Install latest pre-release Python extension version.
2. Set your log level to Trace
3. Make sure Python extension is activated and go open a new terminal
4. Type Python to launch your Python REPL
5. Go to Extension telemetry log output and make sure you see the telemetry event getting fired with "...replType:Terminal" such as: