Blockbase comments block refactor

[MaggieCabrera]

Changes proposed in this Pull Request:

This PR refactors the Post comments block for Blockbase and all its children according to what's discussed on #4515 and #4531
There was some redundant CSS on some of the themes and some that could be refactored into Blockbase to work for all the children.

This is the before and after:

Blockbase:

Before	After

Seedlet:

Before	After

Mayland:

Before	After

Quadrat:

Before	After

Geologist:

Before	After

Skatepark:

Before	After

Related issue(s):

Closes #4515
Partially addresses #4531

[kjellr]

This looks great! Just a few comments:

1. On second thought, let's make the font size of the reply link smaller. I suggest we match the font size of the comment meta (0.75em).
2. Please make sure all of the Reply links are underlined.
3. On Skatepark, it looks like the comment header isn't lining up correctly with the avatar. See the screenshot below.
4. Seedlet doesn't appear to be indenting its comments properly (this is noticeable in your screenshot above too).

Skatepark (Broken)	Quadrat (Correct)

Seedlet, without nesting:

Thank you!

[MaggieCabrera]

This looks great! Just a few comments:

1. On second thought, let's make the font size of the reply link smaller. I suggest we match the font size of the comment meta (`0.75em`).

2. Please make sure all of the Reply links are underlined.

3. On Skatepark, it looks like the comment header isn't lining up correctly with the avatar. See the screenshot below.

4. Seedlet doesn't appear to be indenting its comments properly (this is noticeable in your screenshot above too).

Thanks so much for the quick review! I think I fixed all the points above, this is ready for another review.

[kjellr]

This looks great, thanks Maggie! We may refine more eventually, but this is a great starting point for these, and it's way nicer than what we had before. 🙌

One very tiny thing I noticed in Seedlet Blocks: The spacing above and below each comment should be equal, but right now there's more space at the bottom than at the top:

Feel free to fix that here or in a followup PR! Thank you!

[MaggieCabrera]

Fixed the last thing and bringing this in