adds zarf cache flag

[UncleGedd]

Description

Adds a zarf-cache flag to specify where images are stored on a user's machine.

Related Issue

Fixes issue #402

Type of change

• New feature (non-breaking change which adds functionality)

[UncleGedd]

Currently, the Zarf image cache resides in the home directory and this PR adds the option to put the cache in a subpath within the home directory. Would we like the option to put the image cache outside of the home directory?

[RothAndrew]

@YrrepNoj you were working with someone on something kinda-adjacent to this kind of thing right? IIRC they had very little space on their root drive (where the home directory is mounted) but they had a separate filesystem mount that had tons of space.

Given that, perhaps the user should be able to specify anywhere they want, rather than just somewhere inside their home directory.

[jeff-mccoy]

Thanks @UncleGedd, this is a helpful PR. I think we should discuss moving the flag down to zarf package create though as mentioned by @YrrepNoj.

[UncleGedd]

Thanks @UncleGedd, this is a helpful PR. I think we should discuss moving the flag down to zarf package create though as mentioned by @YrrepNoj.

Easy fix! Will update and add an e2e test for zarf package create

[jeff-mccoy]

Overall looks good and is a valuable addition, only comment is whether the regex for path detection is the best way to do that vs some path function.