Add version command for notation CLI

[yizha1]

Currently notation version doesn't work, user has to use --version to print out the version info, which is limited and generated by CLI framework.

$ notation version
Error: unknown command "version" for "notation"
Run 'notation --help' for usage.
2022/09/21 21:21:41 unknown command "version" for "notation"
$ notation --version
notation version v0.10.0-alpha.3+unreleased

version command is widely used by many command tools, notation CLI should support version command for a stable release. Here is a request to add notation version command, and the following printout is a suggestion for a minimal information to be printed out:

Version: 
Go version:

[FeynmanZhou]

Git commit is necessary information when I build a binary from the main branch. I would suggest to add this field.

[yizha1]

Reopen this issue for implementation is not done.

[yizha1]

• spec: spec: add spec for notation version command #376
• implement version command

[JeyJeyGao]

I will work on this item.