Extract recovery kernel

[frelon]

This PR refactors the deployment of the recovery-system in our different code-branches according to the ADR.

• [x] build-iso
• [x] build-disk
• [x] install
• [x] upgrade-recovery

Fixes #1864 #1930

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 59.52381% with 51 lines in your changes are missing coverage. Please review.

Project coverage is 72.34%. Comparing base (a2c4f0b) to head (ef40072).

Files	Patch %	Lines
pkg/elemental/elemental.go	62.02%	22 Missing and 8 partials :warning:
pkg/action/install.go	30.00%	6 Missing and 1 partial :warning:
pkg/action/build-disk.go	54.54%	4 Missing and 1 partial :warning:
pkg/action/upgrade-recovery.go	37.50%	4 Missing and 1 partial :warning:
pkg/action/build-iso.go	69.23%	3 Missing and 1 partial :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #2016 +/- ## ========================================== - Coverage 72.56% 72.34% -0.22% ========================================== Files 76 76 Lines 8907 8992 +85 ========================================== + Hits 6463 6505 +42 - Misses 1910 1944 +34 - Partials 534 543 +9 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.