Adjust height/bodyweight tests for varying height

[wapcaplet]

Summary

SUMMARY: Infrastructure "Adjust height/bodyweight tests for varying height"

Purpose of change

To make the height/bodyweight biometrics tests more accurate with the new adjustable height, and to exercise some aspect of the relative height-adjustment done in Character::height()

Describe the solution

Changes tests/char_biometrics_test.cpp to account for variable height, and does some tests with different initial heights to ensure that various size mutations (SMALL, LARGE, HUGE) are reflected in the adjusted relative height() return value.

Describe alternatives you've considered

Oblivion

Testing

tests/cata_test [biometrics] --order rand

Additional context

Supports #39385

[wapcaplet]

Some CI failures are from the elite bio-operator issue fixed by #39516 . Not sure what Travis's problem is; says all tests are passing, yet it reports as failed.

[anothersimulacrum]

The issue with travis has since been fixed.
https://travis-ci.org/github/CleverRaven/Cataclysm-DDA/jobs/674215555#L4786

[wapcaplet]

AppVeyor now has a failure with ranged balance tests, no idea how they could be related to this PR:

C:\Projects\Cataclysm-DDA\tests\ranged_balance_test.cpp(235): FAILED:
  CHECK( fast_stats.avg() > hit_rate )
with expansion:
  0.287037037 > 0.45f