Comments: Don't show the filter/pagination actions if there are no comments to list.

It doesn't make sense to be able to filter the comments list table when there are are no (trashed/spam) comments available.

Fixes #40188.
Props swissspidy, Jim_Panse, menakas, akbarhusen429, dinhtungdu, birgire, SergeyBiryukov, davidbaumwald, rebasaurus, whyisjake.


Built from https://develop.svn.wordpress.org/trunk@48521


git-svn-id: https://core.svn.wordpress.org/trunk@48283 1a063a9b-81f0-0310-95a4-ce76da25c4cd