Implement file.decompress

[jabbate19]

What type of PR is this?

/kind documentation
/kind feature
/kind eldritch-function

What this PR does / why we need it:

Implements a decompression method for files and directories. Uses gzip, then tar if applicable for directories. Includes tests and documentation.

Unit Test Results

skyz@DESKTOP-M0SBB8Q:~/realm/implants/lib/eldritch$ cargo test --package eldritch --lib -- file::decompress_impl::tests --nocapture
    Finished `test` profile [unoptimized + debuginfo] target(s) in 0.23s
     Running unittests src/lib.rs (/home/skyz/realm/implants/target/debug/deps/eldritch-2f3839402acc0ece)

running 2 tests
Decompressed single file to /tmp/.tmpKhbV7G_decompressed
test file::decompress_impl::tests::test_decompress_basic ... ok
Decompressed tar archive to dir /tmp/.tmpPCigR5_decompressed
test file::decompress_impl::tests::test_decompress_tar_dir ... ok

test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 190 filtered out; finished in 0.00s

Implementation Demo

File

skyz@DESKTOP-M0SBB8Q:~/realm/implants$ cargo run --bin=golem -- -i
$> file.compress("/tmp/test_content/foo.txt", "/tmp/foo.txt.gz")
$> file.decompress("/tmp/foo.txt.gz", "/tmp/foo.txt.out")
skyz@DESKTOP-M0SBB8Q:/tmp/test_content$ shasum /tmp/test_content/foo.txt 
f1d2d2f924e986ac86fdf7b36c94bcdf32beec15  /tmp/test_content/foo.txt
skyz@DESKTOP-M0SBB8Q:/tmp/test_content$ shasum /tmp/foo.txt.out
f1d2d2f924e986ac86fdf7b36c94bcdf32beec15  /tmp/foo.txt.out

Directory

skyz@DESKTOP-M0SBB8Q:~/realm/implants$ cargo run --bin=golem -- -i
$> file.compress("/tmp/test_content", "/tmp/test_content.tar.gz")
$> file.decompress("/tmp/test_content.tar.gz", "/tmp/test_content_output")
skyz@DESKTOP-M0SBB8Q:/tmp$ shasum /tmp/test_content/*
e242ed3bffccdf271b7fbaf34ed72d089537b42f  /tmp/test_content/bar.txt
f1d2d2f924e986ac86fdf7b36c94bcdf32beec15  /tmp/test_content/foo.txt
skyz@DESKTOP-M0SBB8Q:/tmp$ shasum /tmp/test_content_output/test_content/*
e242ed3bffccdf271b7fbaf34ed72d089537b42f  /tmp/test_content_output/test_content/bar.txt
f1d2d2f924e986ac86fdf7b36c94bcdf32beec15  /tmp/test_content_output/test_content/foo.txt

Which issue(s) this PR fixes:

Fixes #65