Add ability to try a command

[slemeur]

According to the specification #2681 , we need to let the user being able to test a command.

In the command editor's toolbar, we will add a small "run" button, which allow to execute the command.

[TylerJewell]

I have two issues with the ux on this. First, no one sees the play button on the far right. I think it is easy for someone to miss it. Second the nature of the tabbing in the commmand editor seems weird like we are doing too much when what we should really do is have tabs like the editor has.

[slemeur]

We will work on another design. But that will be in a separate issue.