Close all tabs when workspace changes

[yann300]

fix #989

[ryestew]

I think there are a couple of issues.

1. when a learneth file is loaded - so it coming from a .learneth folder
2. a gist
3. when the workspace name has been changed.

I will double check there problems to see if I can recreate the problems.

[ryestew]

I seem to have 2 Readme s up - I'm on workspace_1 -but I have readme from workspace_1 and workspace_2

[ryestew]

Ahhh - so files with the same name in different workspaces have problems turning off

[ryestew]

I'm in workspace_2 and I see

The workspace name is appearing in the tab and it shouldn't

[ryestew]

and by going back and forth between workspaces I eventually got this:

the same contract repeated (1_Storage.sol)

[ryestew]

Nearly there:
I am not getting files with the same names opening when I switch workspaces.

But:
If I have 16 tab open (or 1 tab- but it could be more annoying if I have a lot of tabs open)
and I switch workspaces - when I come back my first workspace - all the tabs (except the home tab) are closed. We could merge this as is and then work on the improvement in the next release.