Fix colspan bug in table block for tables with <thead> tags

[earnjam]

Fixes: #7688

Removing display: table from the tbody tag in the table block appears to solve the issue. I didn't see any negative effects from this in my testing, but it could use some additional testing to make sure there isn't a scenario I didn't come across.

Tagging @jasmussen since he added this line originally in 24011e3 in case it's required for something.

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.

[jasmussen]

I'm afk for a bit so you might want to expand the review range if you'd like a prompt review, but as a sanity check and without testing, this seems good. However you need to be sure to test both the options for fixed width cells in the inspector, and verify that the responsiveness works, that is there is a horizontal scroll bar if there's content on mobile that can't wrap.

[earnjam]

Thanks, no rush. I'm just working through some of the block conversion issues to try to whittle those down ahead of Try Gutenberg. I'll test out some more fixed-width cell scenarios to make sure they work.

[ianbelanger79]

Looks good to me, removing display: table; from .wp-block-table tbody does fix the table display in the editor

[jasmussen]

Sorry for belatedly returning to this PR. I think it broke this control:

How it should work:

How it's broken now:

[earnjam]

Ah, good catch. Sorry about that. Looks like instead of removing display: table, instead we need to just apply the same rules to thead that are on tbody

[earnjam]

@jasmussen Should I open a new PR with the fix or consolidate to #8767?

[jasmussen]

I don't think a fix is urgent. If we know how to fix it, so long as it's on someone's radar or tracked, either is fine. Thanks

[jasmussen]

If you have a recommended fix, I can put together a PR.

[jasmussen]

@earnjam It's important we do not ship 3.7 without this fix. Given that the fixed table cells were not part of #8767, would you like to create a PR for this?

Otherwise let me know how you'd propose the fix, and I can put together.

Alternatively we'll have to revert this.