vita3k/packages: Handle fs errors when installing pkg

[ihopeitdoes]

• Fixes possible crash when installing pkg to disk with low storage space.
• I'm aware of decrypt_fself() in sce_utils.cpp which has a similar problem, which also seems to be very optimistic about it's file operations. I'll get to it eventually.
• Feel free to nitpick, I don't know if my "fix" is really the best solution, I kind of just went off what was already there.

Consideration:

• Update lang "pkg_install/failed_install_package" message to mention something along the lines of "check if there is enough storage space as well"

[Macdu]

While using the non-throwing version, you also changed the call from fs::create_directories to fs::create_directory. The latter will also return an error if the parent directory does not exist (while the former just creates it). I'm not entirely sure if this can happen, but is there a reason for it?

[ihopeitdoes]

While using the non-throwing version, you also changed the call from fs::create_directories to fs::create_directory. The latter will also return an error if the parent directory does not exist (while the former just creates it). I'm not entirely sure if this can happen, but is there a reason for it?

Typo, had it fixed locally forgot to push

[nishinji]

?