Olivero table.css should be in its own library and #attached to tables

Problem/Motivation

Olivero adds table.css to its base library, but the vast majority of pages don't include tables.

I think Olivero could define a table library, move the CSS there, then attach this to all table render elements / #theme table.

This would remove 2.2k of unused CSS on pages that don't have tables.

Steps to reproduce

Proposed resolution

Add a new library, like olivero.table and move table.css there.

Attach the library to tables, probably could be done in olivero_preprocess_table() which already exists.

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet