Refactor: cleanup cmd variable names

[apostasie]

This is a suggestion following on #3913

These changes are purely cosmetic, and their purpose is to increase code readability, by removing stuttering information from variables and functions name (following the refactor of cmd this last summer), and overall simplifying names.

This applies solely to cmd/

For now, these changes are solely on apparmor, so that we can talk about them.

If this is the right thing to do and we agree on the changes, I will apply them to the entirety of cmd and submit a complete / working PR.

The proposed changes are:

• rename all newThingPackageCommand function names to thingCommand:
• rename all packageThingAction function names to thingAction
• rename all processPackageThingOptions function names to thingOptions
• rename top-level NewPackageCommand unique functions to Command
• expand Ls, Rm, to List, Remove where applicable

Reasoning is that:

• Package always stutter now that they are split under cmd
• new, or process does not add much value if any and is just noisy
• acronyms are bad

Thanks.

Tagging @AkihiroSuda for opinion.

[AkihiroSuda]

Thanks