engine-fhir tests improvements

[antvaset]

A few small changes:

• Fixed Log operator evaluation: Log returns null when base is 1. The spec says If the result of the operation cannot be represented, the result is null. (source). Added new test case for log_1(2) in addition to log_1(1).
• Fixed the ranges for the Decimal type: As per the spec, decimal values are in range (-10^28^+1)/10^8^..(10^28^-1)/10^8^, i.e. -99999999999999999999.99999999..99999999999999999999.99999999 (20 nines before the decimal point and 8 nines after the decimal point).
• Added support for Long types in truncated division: 10L div 3L now returns 3L as expected.
• Fixed IndexOf operator evaluation: IndexOf returns null if the element argument is null as per the spec.
• Fixed the Includes_NegInfBegIncludesDateIvl test in the CqlTestSuite library which was failing in NZ timezone: When the lower boundary of DateTime-typed Interval is null, it is set to minimum DateTime which strictly speaking returns DateTime(1, 1, 1, 0, 0, 0, 0, 0) and not DateTime(1, 1, 1, 0, 0, 0, 0).

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 66.66667% with 4 lines in your changes missing coverage. Please review.

Project coverage is 62.26%. Comparing base (e00c396) to head (74bf237). Report is 1 commits behind head on master.

Files	Patch %	Lines
...engine/elm/executing/TruncatedDivideEvaluator.java	0.00%	3 Missing and 1 partial :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1369 +/- ## ============================================ - Coverage 62.26% 62.26% -0.01% - Complexity 6951 6953 +2 ============================================ Files 492 492 Lines 27727 27731 +4 Branches 5506 5508 +2 ============================================ + Hits 17265 17266 +1 - Misses 8198 8200 +2 - Partials 2264 2265 +1 ```

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