Support workspace

[wcampbell0x2a]

Thought I'd try this out on one of my projects: https://github.com/wcampbell0x2a/backhand

$ poetry run fz ../backhand --stop-on bug --max-fuzz-targets 2
API key is set in env var
Checking external dependencies...
[SUCCESS] semgrep
[SUCCESS] cargo fuzz
Warning: failed to run cargo fuzz init
Error: /home/wcampbell/projects/wcampbell/backhand/Cargo.toml (package.name) is malformed

About to autofuzz workspace members:
../backhand/backhand
../backhand/backhand-cli
../backhand/backhand-test

Retrying with workspace member: ../backhand/backhand
Warning: failed to run cargo fuzz init
Error: /home/wcampbell/projects/wcampbell/backhand/backhand/Cargo.toml (package.edition) is malformed

Aborting... could not cargo fuzz init, and not a virtual manifest
Saved fuzzomatic results to: ../backhand/.fuzzomatic_results.json

Final fuzz targets generated for this codebase:
**************************************************
args.codebase_dir='../backhand'
building=0
useful=0
bug_found=0
**************************************************

Code base total duration: 0:00:00.119447

[amietn]

Thank you for giving Fuzzomatic a try!
I believe this currently fails because cargo-fuzz fails to init on crates using edition.workspace = true in Cargo.toml
rust-fuzz/cargo-fuzz#333
It looks like there's already a PR fixing it as well so it should be fixed in cargo fuzz soon.