Add a way to map different package names between package managers.
A new system-packages-map
variable is defined that maps a package
name to a list of package manager / package name key values.
A new system-packages-pack
function is added that fetches the actual
package name for a given package manager using the
system-packages-map
variabl.
The commands functions are updated to first resolve the package name to the actual name.
For example:
(customize-set-variable system-packages-map '("fd" (apt . ("fd-find"))))
will make it so that on system where apt is the package manager, "fd-find" will be used while fd will be used on others.