Get list of PBOs / Rename PBOs

[jonpas]

In order to do operations on all PBOs in a post_release hook we need the ability to get all PBO files in the virtual/real filesystem.

One such use-case is to rename all PBOs, eg. attach a prefix, lower-case all, in cases where prefix does not otherwise match the PBO name. This would be used on CUP projects where mainprefix = "CUP", prefix = "Weapons", but PBO name for addon ACR is CUP_Weapons_ACR while HEMTT names the PBO Weapons_ACR. This is mostly to keep it the same as older releases.

Another use-case is copying in additional pre-built PBOs that we only want to sign in the release process. This would be used for CUP Units Dubbing, which are a bunch of resources separate from the main CUP Units project due to sheer size and zero changes ever applied.

[BrettMayson]

#593