Sticky scroll hides typing on first line in file based program

[dibarbet]

This is could be due to the outline model for C# reporting the <top-level-statements-entry-point> symbol at the top of the file (see #7762 )

Workarounds:

1. Turn off sticky scroll editor.stickyScroll.enabled
2. Switch the editor.stickyScroll.defaultModel value to something other than outlineModel