Revert #6253 and #6257 and make tests use ServerContext when checking internal tables

[ctubbsii]

This is a bit of a strange workaround that I think might lead to unintuitive results in ITs. I think it would have been better to modify the affected ITs to query the fate and scanref tables with the ServerContext instead of the root user's client, because that reflects how Accumulo actually accesses these tables. Modifying the permissions for the tests might mask future permissions issues, and it makes it more difficult to understand the test environment.

Originally posted by @ctubbsii in #6253 (comment)

[dlmarion]

I think we should wait to revert these commits until after we get all of the 4.0 tests fixed. That way we can see exactly how many tests need to be modified.