After we upgraded to QUnit 1.23.1, we gained support for
assert.expect(). This allows us to guard against any race conditions
within tests, because now expect() will be linked to the specific test
instead of the current running test.
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.