Show Gitpod total processing time in minutes for benchmarking

What does this MR do and why?

This MR shows a time to startup a fresh Gitpod instance in minutes to allow us to benchmark this and propose achievable targets where we can reduce this time (gitlab-development-kit#1518 (closed)).

Screenshots or screen recordings

The below are example screenshots of logs for the Gitpod processing time with and without Prebuilds in the browser.

Gitpod workspace started with Prebuilds	Gitpod workspace started from fresh

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.