Tests for Problems view

[sandy081]

Test for #6679

• Windows - @bpasero
• OS X - @weinand
• Show summary of errors, warnings and others in the title
• Group errors, warnings and others by file
• Show file path and count with file name
• Single click on a problem, opens the file and show the problem. Keeps the focus in Problems view
• Double click / Enter on a problem, opens and focus the file at the problem location.
• Auto expands all files with problems
• Filter text box to filter problems by type and text
• Collapse all action