tests: shortcuts like "Lt" should give same as "<"

In Issue #7775, @asmeurer said that `< and Lt should be the same`.  Here are some tests for that (which currently fail).
I suspect 784 tests might be excessive in light of tests which probably already exist. e.g. if we know that args are sympified, do we need S(0) and 0 in the set of items to test? What are I, I+2 and 2*I testing (and why not x, x+2, 2*x, x+y, x*y, x**y)? I'm not saying to add those...I'm just questioning what new has been added by these tests over existing tests.