Description
This is a follow-up to further improve the situation with the problem mentioned in #6479:
Many of us regularly forget to select a template on this step (causing an immediate validation error when we enter the path). ... The reason we forget to select a template so often is because which template is in use is not even something we're thinking about -- because it's not relevant to our current task: placing blocks on the page.
I would argue that it is also because we are assuming that no validation will happen soon as we focus on another element on the form. Either way, even with the template preselected, it is still difficult to distinguish which one is selected, because the difference between selected and unselected tiles is very subtle, and everything is using a gray color (which is usually associated with disabled items/elements):
I propose that we change the above so that the halo around the tile, as well as the image representing the template are blue for the selected option. Something like this: