Common commands are not available in the drop-down. Stack che-in-che.

FYI EXEC drop-down displays running processes but not the commands )
@slemeur What do you think about that, looks like current implementation of command/process panel not clear for user?
I believe there is a "Run" and a "Debug" buttons with a small dropdown too, which are most natural place to do those actions.
Here the confusion is mostly due to way commands were handled in the past.
Still, there are few things we can do to improve:
@azatsarynnyy WDYT ?
I also think that the problem is the misleading placeholder "Start command".
We should tell the user somehow that EXEC drop-down displays the currently running commands (and those which were run) but not all existing ones.
The placeholder with the text like "Nothing running" should be much better and enough I guess.
I propose to close this issue because I actually don't correctly understand the concept.
We have a right issue with an improvement of that entire place. https://github.com/eclipse/che/issues/4993 I propose to move commenting there.