Measure impact of Theia extensions on startup time

[sgraband]

Feature Description:

With the introduction of the performance measurement script in #9777, the startup time of Theia can easily be measured. However, testing what is actually the reason for the negative impact on startup time, can be rather time consuming, as many possibilities need to be tested. One example would be the impact of Theia extensions. To test this the user would need to measure the startup time for a base application, add the extension to the base application and measure the startup time again. This can get really time consuming when a lot of extensions need to be tested.

Therefore, a script that does this automatically would really help to fully leverage the performance measurement script. With this you could easily test each Theia extension separately to get an overview of the impact they have on the startup time (e.g. in the browser example). In the future this script could also be added to an automated CI pipeline, for example the nightly build, to detect eventual regressions early on.