Write a current command that allows shell-friendly output

[marc0der]

A new current command should be written that supports all the functionality of its bash predecessor. A new feature was requested that will allow you to provide a flag (perhaps called --version) that will only return the version of the specified candidate.

For instance:

sdk current --version java
21.0.1-tem%

Note: no newline (shown by the %).

If the flag is not provided, the output should be friendly to humans.