Download external resources preference

[angelozerr]

Download external resources preference

Signed-off-by: azerr azerr@redhat.com

[rgrunber]

One small case I noticed :

1. Open a workspace and do not grant trust. Remote schemas won't download, as expected.
2. Now grant workspace trust
3. The schema still won't download, and will show a message for the download being disabled
4. If you reload the window it should work as expected again

This is because workspace trust is checked once at activation, but we're not using the onDidGrantWorkspaceTrust event. See https://github.com/redhat-developer/vscode-java/blob/master/src/extension.ts#L447-L449 for how to do it. I guess this may also be an issue with resolving entities ?

Update : Also, I think the setting here should be added to restrictedConfigurations in package.json to ensure no workspace is able to override it with its own setting.

[rgrunber]

I'm fine with merging. @AlexXuChen , can address the issue I mentioned in a separate PR.

[fbricon]

thanks @angelozerr!