Provide a "Deploy to OpenShift" command

[fbricon]

Here's the idea:

• if there's at least one Quarkus project in the workspace, then enable a "Deploy to OpenShift" command
• when invoked, the command will:
  • detect if vscode-openshift-tools is installed, if not, propose the user to install it
  • ask the user to select the quarkus project to deploy, if there are several.
  • invoke some (new) vscode-openshift-tools API/command, requesting to deploy the selected project
  • see how to handle already published projects (then re-push them?)

On the vscode-openshift-tools side, it'll be equivalent to selecting a workspace directory deployment.
cc @dgolovin @mohitsuman