Update single with sidebar + large header template part + sidebar

[carolinan]

• [x] Post title and date should be centered vertically
• [x] The headings are forcing the font size using pixels, we should redefine the values for the font size ranges on theme.json
• [x] Spacing in between blocks in general are too tight. We might need to tweak this both globally and individually
• [x] Hide Avatar in comments area
• [x] Use the post meta pattern
• [x] Make the sidebar column use <aside> To do:
• [x] After adding the wrapping group for the aside, the block spacing between the sections in the sidebar is off again.

[MaggieCabrera]

Oh, I forgot to add to the list, can we change the container for the sidebar to use the aside tag?

[carolinan]

Columns can not have a different HTML element but we can wrap it in a group.

[scruffian]

After adding the wrapping group for the aside, the block spacing between the sections in the sidebar is off again.

I pushed a commit to fix this.