Add number of users to the telemetry data

[mrsimonemms]

Currently, the telemetry only provides a randomly generated unique ID and the version number.

To this, we should add the number of registered users. The Segment data should be named something like totalUsers so we can expand this to include active/inactive users in the future

This will likely need some liaison from @gitpod-io/engineering-webapp to understand how best to get the total number of users from the database

[JanKoehnlein]

This is what we do in the server:

gitpod/components/server/ee/src/user/user-service.ts

Lines 44 to 45 in fa62003

	const userCount = await this.userDb.getUserCount(true);
	if (!this.licenseEvaluator.hasEnoughSeats(userCount)) {