Bugfix: Prevent empty subject in 'but do no damage' msgs when dealing no damage

[inogenous]

Summary

Bugfixes "Prevent empty subject in 'but do no damage' msgs when dealing no damage"

Purpose of change

• Addresses one part of Grab messages may be inaccurate and subject is blank #67290 .
• Fixes an issue where hitting an enemy without doing damage would show but do no damage (sic) without the You hit the zombie-part.
• The issue before was:
  • The method melee_message tries to determine which damage type does the most damage
  • But if the attack does 0 damage on all damage types, it would select damage_type_id::NULL_ID as the type of damage being dealt.
  • This meant that the code that determines whether to display You poke the zombie, You cut the zombie or You hit the zombie picked none of them, thus displaying the broken attack messages.

Describe the solution

• This change defaults to bashing damage if none of the other damage types deals any damage, so that the message displayed will be You hit the zombie+ but do no damage
• Bashing damage was the previous choice before this code was refactored in 6141f76#diff-2cd8dac3d0903ca1ee60a47c28e09bcb56290214bc8d1fe5cf4afaed108b9d92R2532-L2715

Describe alternatives you've considered

• Another option would be to pick a random damage type

Testing

Before:

After:

Additional context