target-size should report questionable links in text blocks for review.

I spotted axe-core's target-size rule treating these two very similar lists completely different. This is a link with the letters A through Z linked, as a kind of filter function based on a letter. Despite the links being too close together, the first list is completely inapplicable, while the second list is all failed:


The reason the first one is inapplicable is because some of its letters aren't linked. Axe-core spots that there are non-widget texts in the block with the other links, and so treats everything in that first list as links in a block of text. I did it that way to avoid false positives, but I feel that in cases like that we need better heuristics to work out what is an actual block of text, and what's a list of links, where some items are just disabled, or even where there are some spacer characters separating them.