Improve UX to install system packages without architecture

[czoido]

Provide a better way of forcing installing packages without the architecture appended to the package name even if you are cross-compiling. Currently you can do:

Apt(self, arch_names={}).install(["archless-package"], update=True, check=True)

Passing arch_names as an empty dictionary in the constructor will make that the name resolution skips adding the architecture for all cases (cross-compiling and not). But that is ugly and probably we want to pass a new argument to cover this case.

Related to: #12320

[memsharded]

The workaround is a proper solution, not that much of a workaround, so closing this as solved.