[FEATURE] Improve multi-org workflows

[dagardner-nv]

The Feature Idea or Problem

I'm currently helping two different teams (orgs) with Brev.

I know I can switch between the two orgs with brev org set org1/brev org set org2

It would be nice if other commands like brev shell and brev copy supported a --org flag so that I could quickly do something like:

brev shell --org org1 org1-instance

and then from another terminal do:

brev shell --org org2 org2-instance

Ideally if the Brev CLI was able to search all of my orgs for an instance name then maybe the --org flag wouldn't be needed at all.