Minor changes

Remove ShimmeredDetailsList from the DetailsList 'bundle' (commit by ThomasMichon, pr #5468)

Patches

Check: shouldComponentUpdate now resepects theme and classname changes. (commit by dzearing, pr #5750)
FocusTrapZone: Fix focus/click-trapping bugs when FocusTrapZones are nested. (commit by dagoff, pr #5351)
Restore accessible labels for DetailsList columns and states (commit by ThomasMichon, pr #5740)
dragStart callback will be in sync with browser, instaed of calling it in mousemove (commit by laxmikankanala, pr #5688)
PersonaCion will render the user's avatar image only if there is a valid image and the user do not wish to hide it, unlike previously where an empty img tag(src='') was being rendered over the initials always (commit by s-vaibhav, pr #5678)
Deprecating 'borderStyle' prop of Shimmer subcomponents Line, Circle, Gap in favor of leveraging mergeStyles API. (commit by Vitalius1, pr #5739)