[BP-1.11][FLINK-19587][table-planner-blink] Fix error result when casting binary as varchar

[wangxlong]

What is the purpose of the change

1. This is a backport of FLINK-19587 for 1.11, cherry picked from commit d9b0ac9.
2. Cherry pick commit b2f8866 to support new type system for ExpressionTestBase. This also allows to use new type system in ExpressionTestBase for 1.11 later.

Brief change log

cherry d9b0ac9
cherry b2f8866

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Last check on commit a56eb8b (Wed Oct 28 12:54:01 UTC 2020)

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[wuchong]

LGTM.