Implement a conflict handling strategy for CLI plguins

[iocanel]

Description

Currently CLI plguins may have conflict and there is not policy / strategy in place to short this out.

Conflict examples:

• A script called quarkus-kill will conflict with quarkus-kill from the jbang catalog.
• Two extension providing a plugin with the same name / alias with an exisiting plugin

What currently happens, is not defined anywhere and also users don't know how to change that.

What we need:

• [ ] quarkus plug list --installable should allow listing more than one plguins with the same name alias.
• [ ] Esure quarkus plug add allows plugins to be installed by location
• [ ] Prompt users when adding a plugin that alreay exists.

Implementation ideas

No response

[quarkus-bot[bot]]

/cc @ebullient (cli), @maxandersen (cli,jbang), @quarkusio/devtools (jbang)