- Optimize generting random files.
- Reduce big file of 128MiB to 32MiB (git was never made for large files
anyways, but simply tests that it works).
- Reduce looped git operations from 100 iterations to 10.
- Add extra print statements to know what a slow test is doing, this
also helps to see if a particular piece of code in a slow test is the
culprit or if the test is just very extensive.
- Set `[ui.notification].EVENT_SOURCE_UPDATE_TIME` to 1s to speed up
`TestEventSourceManagerRun`.
- Sneaked in some general test improvements.
