Fix Servers tree action buttons for servers defined in a workspace folder

[isc-bsaviano]

• Fixes No actions possible #284
• Hide the view and edit code commands. It doesn't make sense to allow the creation of server-side workspace folders for servers that are defined within a workspace folder. The created server-side folders will not work.
• Fix the SMP commands.

[gjsjohnmurray]

I think the addition of a suffix risks affecting other extensions that may be adding commands on tree items whose context keys end with "namespace". Instead of breaking those, could your solution add a prefix which the "add ISFS folder to workspace" commands could test (negatively) for?

[gjsjohnmurray]

I have proposed (untested) changes intended to avoid increasing the number of /-pieces in the context key, as a precaution against breaking any existing extensions. The new wsfolder indicator is now a colon-separated prefix on the existing second slash-separated piece.

[isc-bsaviano]

@gjsjohnmurray I verified that the extra slash portion didn't break anything in the main extension. I think that any change would be backwards-incompatible so unless we have evidence that this specific approach is causing changes I think we should stick with it. What other extensions contribute commands to the Servers tree? Your Webterminal one?

[gjsjohnmurray]

These are the ones I'm aware of:

Based on a quick look at their settings.json files they shouldn't be affected by your change, so I'm approving.

[isc-bsaviano]

Thanks for checking John!