Don't require names in blocks lists for blocks with titles

We duplicate the title of most source blocks both in the block itself and in the blocks list

We should default this so that we don't need to write it twice.

Some things to check if/when we do:
* Make sure it works in prep and day-plan TOC
* Make sure it works in overview
* Make sure it works in nested blocks
* Keyboard interactions need to still work, because they're all title based
* We use these in anchors in links
* May need a link checker that supports fragments
* May need to ban inter-sprint links