feat(kds): add metrics to event based watchdog

[jakubdyszkiewicz]

Checklist prior to review

This PR adds more granular metrics to kds reconciller and unit tests to the experimental watchdog.

We want to measure what triggered watchdog flush (event or resync) and what is the result (was something changed or did we waste CPU time). This way we can discover how useful is resync and whether we can change the resync of 60s to something like 5mins or 1h etc and save CPU resources.

• Link to relevant issue as well as docs and UI issues --
• This will not break child repos: it doesn't hardcode values (.e.g "kumahq" as a image registry) and it will work on Windows, system specific functions like syscall.Mkfifo have equivalent implementation on the other OS --
• Tests (Unit test, E2E tests, manual test on universal and k8s) --
• Do you need to update UPGRADE.md? --
• Does it need to be backported according to the backporting policy? (this GH action will add "backport" label based on these file globs, if you want to prevent it from adding the "backport" label use no-backport-autolabel label) --
• Do you need to explicitly set a > Changelog: entry here or add a ci/ label to run fewer/more tests?