Improve install size report

[43081j]

We should do this more like how size report does it (another GH action).

Basically a table where each package before/after has one row rather than two.

Right now, if pkg-a goes 1.0.0 to 2.0.0, we show 2 rows with the size of each (positive or negative based on if it is added or removed). This should be one row which shows +/-.

Kinda like this:

Name	Size
pkg-a	-200KB

rather than this:

Name	Size
pkg-a@1.0.0	-400KB
pkg-a@2.0.0	+200KB

in the latter (current situation) they are total sizes of the package. in the former we're showing the diff