Table block: Allow selection of entire rows and columns

[mapk]

Right now the Table block only allows the selection of a single cell. It would be great to allow selection of an entire row or column. Check out how Google Docs does this below.

[mapk]

This was noted in #16111 (comment).

[talldan]

I have a draft PR where I've started working on this - #16493

I had a look at document editors like atlaskit and dropbox paper (requires signup), both provide table, column and row selection buttons around the table. I thought this would be a good place to start. What do you think @mapk?