Simplify conan inspect command, removing path subcommand.

[czoido]

Changelog: Simplify conan inspect command, removing path subcommand.
Closes: #12247

TODO: consider to add inspection of references in local cache and remotes, some ideas:

conan inspect conanfile.py
conan inspect --requires=zlib/1.2.11 --> goes to the local cache

I would leave the inspect on remote case for users to implement their own using custom commands or maybe:

conan inspect --requires=zlib/1.2.11 --cache --> goes to the local cache
conan inspect --requires=zlib/1.2.11 --remote=remote --> goes to the remote