Add `--quiet` parameter to `asdf install`

[strokirk]

Is your feature request related to a problem? Please describe

As part of our normal setup scripts we tend to add asdf install | sed '/is already installed/d' so we can reduce the terminal noise when nothing needs to be done.

Describe the proposed solution

I would like to see a -q/--quiet parameter being added to asdf install, or simply a ASDF_QUIET=1 / QUIET=1 env variable I can set in our setup scripts that would work for all commands.

Describe similar asdf features and why they are not sufficient

None.

Describe other workarounds you've considered

Adding a sed pipe where necessary.

asdf install | sed '/is already installed/d'

[threkk]

I like the idea behind this. Should this remove all the messages or just some of them?