dillon1000/react

Update gate pragma to detect global error events (#28591)

If a global error event is dispatched during a test, Jest reports that
test as a failure.

Our `@gate` pragma feature should account for this — if the gate
condition is false, and the global error event is dispatched, then the
test should be reported as a success.

The solution is to install an error event handler right before invoking
the test function. Because we install our own handler, Jest will not
report the test as a failure if a global error event is dispatched; it's
conceptually as if we wrapped the whole test event in a try-catch.