AlloyEdior allows running the commands to manipulate the table content only when active element is `td` or `th`. So there is no need to have "insert rows"/"insert columns" buttons in "table" and "table row" toolbars.

Steps to reproduce:
1. Insert a table using the Online Editor
2. Using elements path click on "table" or "tr"
3. Try to insert new rows/cells

Current results:
No new rows/cells are inserted

Expected result:
New rows/cells will be inserted

This happens because of https://github.com/liferay/alloy-editor/blob/master/src/plugins/tabletools.js#L821