This adds `StopPropagation` modules that will stop the propagation
of the most common events from the selection and dropdown containers.
These modules work from a list of 21 common events, most of which
were stopped by default in past versions, and call `stopPropagation`
on them when they are detected at the container level.
These modules are only available in full builds of Select2.
This closes https://github.com/select2/select2/issues/2033.
This closes https://github.com/select2/select2/issues/2974.
