Add unit tests for get_hit, get_dodge and related functions

[wapcaplet]

Summary

SUMMARY: Infrastructure "Add unit tests for get_hit, get_dodge and related functions"

Purpose of change

Improved test coverage of melee aspects

Describe the solution

Adds tests/melee_dodge_hit_test.cpp with unit tests focused on these methods from

• player/monster/Character get_hit_base
  • monster hit base is just skill level
  • player hit base is DEX / 4
• player/monster/Character get_dodge_base
  • monster dodge base is just skill level
  • player dodge base is DEX / 2 + dodge skill
• player get_dodge (in progress)
  • cannot dodge while asleep/narcotized or winded
  • bear trap reduces dodge to 1/2
  • bouldering reduces dodge to 1/4
  • rollerblades/skates/heelys reduce dodge to 1/5 (or 1/2 for pro skaters)
  • grabs reduce dodge (1 grab = 1/2, 2 grabs = 1/3 etc.)
  • speed reduces dodge linearly (90 speed = 90% dodge etc.)
• monster get_dodge
  • cannot dodge while downed
  • trapped or tied: 1/2 dodge
  • unstable footing: 1/4 dodge

Describe alternatives you've considered

Unexplored mystery

Testing

tests/cata_test [melee][hit],[melee][dodge]

Additional context

This went through some rough (and I do mean rough) drafts, but I have rebased it into two clean commits now.

[wapcaplet]

Several of these tests are randomly failing, even with the same execution order. Common failures are when avatar mysteriously has 1/4 the initial dodge level (causing all others in that section to fail), or when one of the four monsters in the "grab" test are checked for positioning, for example:

Using bash to run the same tests multiple times:

for i in `seq 10`; do ./tests/cata_test [dodge][grab] -d yes; done

The Travis CI run on this PR had a new failure I've not seen locally:

Note, this CHECK is occurring immediately after clear_character, and a couple of REQUIRE statements to ensure the expected DEX and dodge skill - yet it still randomly sometimes comes up 1.0 or 2.75.

[wapcaplet]

Using clear_map before each test mitigates (but does not eliminate) the random failures.

[wapcaplet]

I believe the random failures can be traced to a problem with the clear_character helper function; this function was erroneously setting the position of the global avatar g->u, rather than setting the position of the avatar instance passed to the function as dummy. This is now fixed, and the random failures have been eliminated.

[mlangsdorf]

I'm adding a melee stats counter in #39564 which may or may not simplify some of these tests.

[wapcaplet]

CI test failures here in crafting_test.cpp and vehicle_interact_test.cpp appear to be legitimate for once - I believe they are a side-effect of the additional cleanup steps I have done in clear_character, and I can reproduce them locally. I can also confirm that the errors do not happen without my changes to clear_character.

Now I just need to figure out how on earth having a cleaner starting avatar is causing crafting failure...