Issue #2982582 by arunkumark, nexusnovaz, anish.a, avpaderno, smustgrave,...

Issue #2982582 by arunkumark, nexusnovaz, anish.a, avpaderno, smustgrave, joachim, godotislate, larowlan, cburschka: hook_requirements() doesn't say that severity is optional, or what the default is

(cherry picked from commit c16b8425)