Stick result pagination to top

Author: Benjamin Muskalla

extensions/ql-vscode/src/view/resultsView.css

@@ -15,6 +15,10 @@
   display: flex;
   padding: 0.5em 0;
   align-items: center;
+  top: 0;
+  background-color: var(--vscode-editorGutter-background);
+  position: sticky;
+  z-index: 1;
 }
 
 .vscode-codeql__table-selection-header-item {