Implement local file system support for `secrets cat`

[aryanjassal]

Specification

This is a continuation of Polykey-CLI#243. In that issue, a secrets cat was created with support for concatenating the output of multiple files from multiple vaults in order. It can also take in stdin and output that straight to stdout.

The secrets cat command currently only operates on vault's encrypted file system, and not on the actual user's file system. For consistency, we to support that out-of-the-box.

Additional context

• Continuation of Polykey-CLI#243.

Tasks

1. Allow secrets cat to concatenate system files along with vault files
2. Add fast-check tests if not already implemented

[linear[bot]]

ENG-413 Implement local file system support for `secrets cat`

[CMCDragonkai]

This is pretty low priority, you're talking about secrets cat ./abc vault1:/abc right?

[aryanjassal]

This is pretty low priority, you're talking about secrets cat ./abc vault1:/abc right?

Yes. This is low priority, and will work as you have written.