[Feature Request] adding a Kernel generation option in the Mariner build system

[ohault]

Many interesting Kernel modules and not always available as loadable modules and/or the default enabled modules are not always matching your specifics needs/regulatory requirements.

The current Mariner build system already support generating Mariner images and packages. The goal of this ticket is to implement a third mode to generate Mariner's kernel with default or custom Kconfig

It could be delivery/maintained as a container image for (re)building the kernel for both WSL and Mariner (see https://github.com/microsoft/CBL-Mariner/issues/3549)