Fixed padding for line-numbers in Editor Lite

We add a custom CSS class to the instances of the Editor Lite that
is used to apply styles with higher specificity in the dedicated
stylesheet

app/assets/javascripts/editor/editor_lite.js

@@ -11,6 +11,7 @@ export default class Editor {
     this.instance = null;
     this.model = null;
     this.options = {
+      extraEditorClassName: 'gl-editor-lite',
       ...defaultEditorOptions,
       ...options,
     };

app/assets/stylesheets/framework.scss

@@ -70,3 +70,4 @@
 @import 'framework/system_messages';
 @import "framework/spinner";
 @import 'framework/card';
+@import 'framework/editor-lite';

app/assets/stylesheets/framework/editor-lite.scss

+.monaco-editor.gl-editor-lite {
+  .line-numbers {
+    @include gl-pt-0;
+  }
+}