Add subcommands alias

[jordeu]

Ex:

compute-env -> ce
credentials -> creds
pipelines -> pipes

[pditommaso]

Nice, think even without s

compute-env -> ce
credentials -> cred
pipelines -> pipe

[jordeu]

There is a bug at picocli library when generating the autocompletion scripts for the subcommands aliases:
remkop/picocli#1388

This will be implemented when this bug is fixed.

[jordeu]

picocli 4.6.2, fixing the issue with subcommand aliases, has been released.
https://github.com/remkop/picocli/releases/tag/v4.6.2

[jordeu]

The only difficulty of this issue is to decide which is the best alias. Let me do a proposal and if we agree on it we can add this to 0.5 release.

Main commands:

• actions ->
• collaborators ->
• compute-envs -> ce
• credentials -> creds
• info ->
• launch ->
• members ->
• organizations -> orgs
• participants ->
• pipelines -> pipes
• runs ->
• teams ->
• workspaces -> ws

Subcommands:

• list -> l
• view -> v
• delete -> d
• create -> c
• update -> u
• export -> e
• import -> i
• leave -> (also at commands that have list subcommand)
• relaunch -> r (only at runs command`)
• cancel -> c (only at runs command`)

[pditommaso]

Think in the shortcut the s can be omitted (apart ws..`) eg.

actions -> action
collaborators -> collab
compute-envs -> ce
credentials -> cred
info -> into 
launch -> launch
members -> member
organizations -> org
participants -> ??
pipelines -> pipe
runs -> run 
teams -> team
workspaces -> ws

[jordeu]

Picocli v4.6.2 do not fixed the autocomplete. Still the completion of the subcommands using alias is not working:

I'm going to label this as "on hold" again. We need to report this to picocli because it seems it is not reported.

[jordeu]

New picocli released: https://github.com/remkop/picocli/releases/tag/v4.6.3

Some improvements on alias autocompletion. We can give it a try again.