install: Add --karg-delete

[hone]

Following up from the contribfest session. This adds --karg-delete to install.

In some relatively rare use cases, one might want to remove a kernel argument shipped in the container image.

Fixes: #1229

[gemini-code-assist]

Code Review

This pull request introduces the ability to remove kernel arguments during installation via a new --karg-delete CLI option and a corresponding karg-deletes field in the installation configuration. The implementation includes logic to process these deletions before applying new arguments, a helper function for precise or key-based removal, and comprehensive unit and integration tests to verify the functionality. I have no feedback to provide.

[hone]

I wasn't sure about a few things when implementing this.

1. What is the preferred order of precedence for how --karg and --karg-delete interface. kargs can come from root_setup, install_config, and the CLI. In order to let you delete kargs and allow you to replace it with a CLI flag, I deleted the kargs before applying the CLI flags.
2. Do all install CLI flags also get applied to config? I modeled a configuration option based off of kargs.
3. I wasn't sure which tests to add, so I added some unit tests, integration, and tmt tests.