## What changes were proposed in this pull request?
The previous strategy for comparing Maps leveraged sorting (key, value) tuples by their _.toString. However, the _.toString representation of an arrays has nothing to do with it's content. If a map has array keys, it's (key, value) pairs would be compared with other maps essentially at random. This could results in false negatives in tests.
This changes first compares keys together to find the matching ones, and then compares associated values.
## How was this patch tested?
New unit test added.
Closes#23789 from ala/compare-map.
Authored-by: Ala Luszczak <ala@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
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