Proposal - add ability to determine actual position of popover

[nullifiedtsk]

It's a proposal.

Can you add the typings (or expose them) to the classList object of Popover component ?

Or maybe to add another property that will contain the actual values (not the passed xAlign/yAlign values, but calculated ones)?

This may be helpful when someone is replacing the styling of popup with custom template (with custom carets, baloons, e.t.c.), for, e.g. determination where caret should be located in some complex scenarios?

enum TooltipPositionClass {
  Before = 'sat-popover-before',
  After = 'sat-popover-after',
  Above = 'sat-popover-above',
  Below = 'sat-popover-below',
  Center = 'sat-popover-center',
}

interface SatTooltipPositioning {
  [TooltipPositionClass.Before]: boolean;
  [TooltipPositionClass.After]: boolean;
  [TooltipPositionClass.Above]: boolean;
  [TooltipPositionClass.Below]: boolean;
  [TooltipPositionClass.Center]: boolean;
}

[isaackehle]

I'm good w/ that change. Can you submit a PR?