[Feature]: kernel packages retention

What is the installation method of your PatchMon server?

Docker

What is the version of your PatchMon server?

2.0.2

Briefly describe the feature

Enable old kernel packages removal

Detailed description

Make it possible to configure how many kernel packages you want to keep installed, and remove anything older.

In unattended-upgrades, this feature exists and is configurable with Unattended-Upgrade::Remove-Unused-Kernel-Packages "true";
Would be great if patchmon could integrate something similar.

Why is this useful?

To prevent the root partition disk from filling up when installing kernel updates.