check for org connection

[mshanemc]

Is your feature request related to a problem? Please describe.
I mostly work in short-lived scratch orgs. When I open VSCode, no check is performed to see if the last org is still around. Therefore

• I get an error message when it tries to refresh the sobject defs
• commands that should not be available (push/pull/etc) seem available but will error out
• the org is still shown down in the bottom
• I get a huge amount of dead orgs remaining in the local filesystem (.sfdx)

Describe the solution you'd like
On open, and after a while of not using, check the connection to the org and update the bottom tray and command list, and remove dead orgs from .sfdx

Describe alternatives you've considered
Dismissing error messages every time I open vscode
manually use org:display to see if it's still around
periodically delete .sfdx folder on projects

[git2gus]

This issue has been linked to a new work item: W-16501337