Add support for text editor actions "go to next annotation" & "go to previous annotation"

[travkin79]

Editors like CDT's C++ editor and JDT's Java editor have support for the tool bar actions "next annotation" & "previous annotation" for navigating to the next / previous occurrence of a symbol / identifier (see action bar buttons).

These buttons are also activated for the LSP-based C++ editor, but nothing happens if you push them. It would be great if that could be fixed.

It turns out, LSP4E provides extensions for the extension point org.eclipse.ui.editors.markerAnnotationSpecification, but a few keys are missing and that's why the navigation does not work.

[travkin79]

Thanks for your help, @ghentschke.