Lexical: Updated URL handling, added mouse handling

- Removed URL protocol allow-list to allow any as per old editor.
- Added mouse handling, so that clicks below many last hard-to-escape
  block types will add an empty new paragraph for easy escaping &
  editing.

resources/js/wysiwyg/services/__tests__/mouse-handling.test.ts

@@ -0,0 +1,51 @@
+import {
+    createTestContext, destroyFromContext, dispatchEditorMouseClick,
+} from "lexical/__tests__/utils";
+import {
+    $getRoot, LexicalEditor, LexicalNode,
+    ParagraphNode,
+} from "lexical";
+import {registerRichText} from "@lexical/rich-text";
+import {EditorUiContext} from "../../ui/framework/core";
+import {registerMouseHandling} from "../mouse-handling";
+import {$createTableNode, TableNode} from "@lexical/table";
+
+describe('Mouse-handling service tests', () => {
+
+    let context!: EditorUiContext;
+    let editor!: LexicalEditor;
+
+    beforeEach(() => {
+        context = createTestContext();
+        editor = context.editor;
+        registerRichText(editor);
+        registerMouseHandling(context);
+    });
+
+    afterEach(() => {
+        destroyFromContext(context);
+    });
+
+    test('Click below last table inserts new empty paragraph', () => {
+        let tableNode!: TableNode;
+        let lastRootChild!: LexicalNode|null;
+
+        editor.updateAndCommit(() => {
+            tableNode = $createTableNode();
+            $getRoot().append(tableNode);
+            lastRootChild = $getRoot().getLastChild();
+        });
+
+        expect(lastRootChild).toBeInstanceOf(TableNode);
+
+        const tableDOM = editor.getElementByKey(tableNode.getKey());
+        const rect = tableDOM?.getBoundingClientRect();
+        dispatchEditorMouseClick(editor, 0, (rect?.bottom || 0) + 1)
+
+        editor.getEditorState().read(() => {
+            lastRootChild = $getRoot().getLastChild();
+        });
+
+        expect(lastRootChild).toBeInstanceOf(ParagraphNode);
+    });
+});