Updated codeblock editor to work with fade animation

- Added fadeIn to animation JS service.
- Updated overlay to use anim service and to recieve a callback for
after-anim actions.
- Updated code editor popup to refresh Codemirror instance layout after
animation has completed.

Fixes #1672

resources/js/vues/code-editor.js

@@ -3,7 +3,9 @@ import codeLib from "../services/code";
 const methods = {
     show() {
         if (!this.editor) this.editor = codeLib.popupEditor(this.$refs.editor, this.language);
-        this.$refs.overlay.components.overlay.show();
+        this.$refs.overlay.components.overlay.show(() => {
+            codeLib.updateLayout(this.editor);
+        });
     },
     hide() {
         this.$refs.overlay.components.overlay.hide();