Allow setting active version to installed version in one step

[iroddis]

Is your feature request related to a problem? Please describe

It's frustrating that installation and setting an active version are two distinct steps.

Describe the proposed solution

Add the same switches from asdf set to asdf install such that, if provided, the install also runs set with the appropriate flag.

asdf install -u some_plugin latest   # install and set at the user level
asdf install -p some_plugin latest   # install and set at parent
asdf install -s some_plugin latest    # install and set locally ... using -s as there's no equivalent

Describe similar asdf features and why they are not sufficient

The above is possible with two commands; this feature request is just a qualify of life improvement.

Describe other workarounds you've considered

Just running the two steps individually.