I found myself wanting to quickly see if my changes to the test files
still compiles the tests. Hence this rule.

Also fix all the tests whose keys and other attributes changed due to
having a different schema (all mutation explain tests were moved to use the
previous schema used by query explain tests.).

This commit makes some changes that would let us reuse some code that
will also be needed for the new explain setup. As the explain testing
setup will build on top of this, I wanted this to be a separate commit.
Hopefully not too bad to review.

Example to see the old and new testing sie by side.

Note: This commit will be dropped before merge, it is there only to
help visualize the usage of the new explain test setup.

For example:
- Fail if given an empty request for a non-transactional test.

One additional thing I crammed into this commit was to handle a list of
map to also be copied while copying a map.

Also changes the example tests to ensure the order works, and
sort the keys in sorted order of map (for more visual clarity).