Use cases for an "HMC Information Portal"

Collection of use cases for an "HMC Information Portal" along the lines of the box "User stories and acceptance criteria" in this MURAL board of CCT5

@Witold.Arndt @karl-uwe.stucky @konstantin.walter @clemster @lucas.kulla @esoeding @oonagh.mannix @a.strupp and, of course, everyone else interested: Please feel free to add use cases in the discussion below!