Remove duplicated tests.

[1uc]

There's (at least) three attempts at testing read/write cycles for multi-dimensional arrays. The first is whatever is in tests_*multi_dims.cpp. Since it's partial, a second attempt was made: the first half of test_all_types.cpp. Since this was still partial and not quite DRY enough, a third attempt was made.

This PR removes the duplicated tests from the first and second attempt, one-by-one. Each commit removes one test. Or moves/reimplements a test if it's not yet covered by the third attempt.

There's a fourth attempt in test_high_five_base.cpp; but that's left for another PR.

[1uc]

If it helps reviewing, we could split out the commits that move code, e.g. compare_arrays into a separate PR. Then this one will be removing code and reimplementing the odd test; but no refactoring.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 84.81013% with 12 lines in your changes are missing coverage. Please review.

Project coverage is 86.40%. Comparing base (5f3ded6) to head (2e4a41a).

Files	Patch %	Lines
tests/unit/compary_arrays.hpp	52.00%	12 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1011 +/- ## ========================================== - Coverage 86.81% 86.40% -0.41% ========================================== Files 100 102 +2 Lines 6081 5901 -180 ========================================== - Hits 5279 5099 -180 Misses 802 802 ```

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[alkino]

Nice to split test_boost and test_stl as test_opencv and test_xtensor already are. For the next time, maybe a test_eigen?

[1uc]

Interesting, I thought I'd split them out already, but yes, they can get split away too.