[Improvement] Comment migration: Consider pages with updated comments as changed #100

Release 1.9 introduced comment migration for pages.

Changes in comments are not considered changes in pages, so when checking for page updates WikiTraccs won't detect pages with modified comments as changed.

WikiTraccs should be able to detect comment changes as page changes.

Technical note: checking for comment changes might involve checking each single page, which is different to checking if page content changed, which can be done in bulk for many pages. Need to keep that in mind to now slow down things.