Issue #1808478 by Mile23, prhavile, naveenvalecha, llbbl, hctom, nikunjkotecha, Lars Toomre, deepakaryan1988, mrjmd, jgeryk, mlevasseur: Add missing type hinting to Comment module docblocks

Issue #2516690 by mlevasseur, joshi.rohit100: Missing test for "Help" links per module on "Extend" admin page