Check if VG or LV already exists before creating

[matbme]

[taukakao]

Might become redundant because of https://github.com/Vanilla-OS/vanilla-installer/pull/373

Because I'm not sure if this is really the job of Albius. The program creating the recipe should check what vgs need to be added or removed. The user of Albius might not expect it to make changes to the LVM configuration if it's not told to do so.

[matbme]

The user of Albius might not expect it to make changes to the LVM configuration if it's not told to do so.

True. At most, Albius should warn or throw an error when a VG or LV with the provided name already exists. I'm removing the Orchid tag since the issue if fixed on our side.