Add telemetry event when startup is over 30 seconds

[TylerLeonhardt]

Summary of the new feature

We recently added #2653 a notice to the user after 30 seconds that says "it's taking longer than expected to start up"

We should also add a telemetry point to capture when this happens so we can see how frequent it occurs. If it occurs a lot, then we can prioritize startup perf.

Proposed technical implementation details (optional)

Added telemetry event called "SlowStartup" that basically captures:

• OS (provided by vscode telemetry module)
• VS Code version (provided by vscode telemetry module)
• PS ext version (provided by vscode telemetry module)
• PS version

this basically is a copy-paste of our exist telemetry point:

vscode-powershell/src/session.ts

Lines 541 to 542 in 7dadd34

	this.telemetryReporter.sendTelemetryEvent("powershellVersionCheck",
	{ powershellVersion: versionDetails.version });

cc @rjmholt @SydneyhSmith @SteveL-MSFT

[TylerLeonhardt]

Potentially worth including a telemetry point when the timeout is exceeded as well.

[EdCallahan]

A couple notes about the WaitForSessionFile logic cleanup at #2653 that might effect how you implement telemetry, or at least the data you can hope to collect via telemetry.

When the session file is not found because of BeyondTrust/Avecto privilege management, VS Code is unresponsive. The user gets the "The window is no longer responding" dialog periodically:

When the session file is found, or the timeout is hit, the warning message is shown at the same time as the "Language service could not be started" message. The "Loading is taking longer than expected" is not shown at powershell.developer.waitForSessionFileNumOfTries / 2, it is shown when the session file is found, the timeout is exceeded, or sometime after that. But the two dialogs appear at the same time.

VS Code can stay unresponsive well past the powershell.developer.waitForSessionFileNumOfTries timeout. 5 minutes or more.

A believe this is an Avecto problem, not a code problem. But I mention it because if the telemetry is silent that will not mean there is not a problem. I assume that while VS Code is unresponsive it simply will not send telemetry.

[TylerLeonhardt]

I assume that while VS Code is unresponsive it simply will not send telemetry.

This is a good point. Thanks @EdCallahan