Feature
#364 Add a sub command which, which outputs the file path of the given command
$ aqua which <COMMAND>
e.g.
$ aqua which golangci-lint
/home/runner/.aqua/pkgs/github_release/github.com/golangci/golangci-lint/v1.42.1/golangci-lint-1.42.1-linux-amd64.tar.gz/golangci-lint-1.42.1-linux-amd64/golangci-lint$ aqua which go
/opt/hostedtoolcache/go/1.17.2/x64/bin/goOthers
Add tests