Refactor and improve test 514

Refactor and improve test 514

Split test 514's assertion into three assertions to make it more
explicit what is being tested, and why a run might fail.

Move critical test code out of the event handler to clarify flow and
allow a query of the actual current workspace to use in assertions.

Works around an issue which caused this test to fail spurriously because
of pointer-related quirks in the i3 test suite which would sometimes
cause i3 to open on workspace 2 (However, the test is now agnostic to
the initial workspace or output).