Add system-agent installation script to etcd restore

[alexander-demicev]

What this PR does / why we need it:

• Add system-agent installation script to etcd restore, it's a modified version of https://github.com/rancher/system-agent/blob/main/install.sh, we should make some changes in system-agent repo and also use this script so don't have to duplicate efforts, for now, let's have our version to not block development.
• Fix webhook configuration
• Add insecure skip verify to etcd restore webhook and also tilt support for it

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged): Fixes https://github.com/rancher/turtles/issues/497

Special notes for your reviewer:

Checklist:

• [ ] squashed commits into logical changes
• [ ] includes documentation
• [ ] adds unit tests
• [ ] adds or updates e2e tests

[furkatgofurov7]

@alexander-demicev please link the corresponding issue from the list if it applies in the PR description, thanks!

[alexander-demicev]

@Danil-Grigorev we can collect system logs for it's service