Flexible layout templates: Allow custom ID for rows

When I configure a Flexible layout row, I want to add an id attribute for the row. Setting an ID would allow linking to a row using a URL fragment. Example:

• Row: <section id="about" ...>
• Link: <a href="#about" ...>

The custom ID would be very helpful building one pager websites or landing pages where navigation links point to different sections of the same page.

At the moment, it's possible to add a Region name and an Additional row class via the "Configure row" dialog. I suggest to also provide the option for a custom ID.

Alternatives that have been considered I didn't find a way to set custom IDs via the Flexible layout template or via the configuration file of a Flexible layout.