Increase CSS specificity on Inline Comment Summary

Summary: Fixes T8354. Adds a class to each th and td for specificity.

Test Plan: Write a large table as an inline comment, see it wraps property on smaller screens.

Reviewers: btrahan, epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T8354

Differential Revision: https://secure.phabricator.com/D13076