Fix invalid property class name parsing

[gRegorLove]

The nestedMfPropertyNamesFromClass method was parsing property classes regardless if they were valid (e.g. p-4). Updated the method to use existing mfNamesFromClass method, which uses the correct regex to skip those classes.

Also fixed a test for nestedMfPropertyNamesFromClass which asserted the response array was equal. The expected and actual response array had the same values, but in different order. The order is not important in that response, so I switched the assertion to assertEqualsCanonicalizing.

This also appeared to fix #246, so I added a test to confirm that.

Fixes #249
Fixes #246

[gRegorLove]

Note there's still three "risky" tests that don't perform assertions. I didn't update those in this PR but can in a subsequent one.

[sknebel]

LGTM, matches what I expect, but would like second review from someone deeper in PHP

[gRegorLove]

Added an additional test that @sknebel provided:

<div class=" h-5 pt-2">
	<div class="p-4 h-entry">
		<a class="u-url" href="https://example.com/bar">bar </a>
	</div>
	<div class="p-4 h-entry">
		<a class="u-url" href="https://example.com/foo">foo</a>
	</div>
</div>

Parsed empty on http://php.microformats.io/?id=20231011231942570