Make TestClusterScopeQuotaThrottle run faster

-The test always times out and it has several test methods.

Let's split the test into several smaller tests, so we can find out which one is the criminal.-

Finally I found that, the problem is we does not limit the operation timeout, just set the max retry number, but after some new improvements come in, sometimes we may get a 6 min sleep time and n doubt we will get a test timeout...

I changed the test a bit to set operation timeout on the Table instance we use, so it will fail immediately when we hit the quota throttling, and now the tests could finish very soon.

I think we could add another E2E tests to make sure that the refilling works as expected.