fix(regeneration): make the painkillers worth taking in a chase

[theEvilReaper]

Proposed changes

In playtests the painkillers gave back barely half a heart when the slender was nearby, because every hit also ate away the healing that was still to come. Now a hit only costs health, and the healing continues once the survivor gets away. Fear also slowed the healing down so much that it hardly did anything right after a chase. Now even a terrified survivor heals at half the normal speed, and this can be adjusted in the config.

Types of changes

What types of changes does your code introduce to this project?
Put an x in the boxes that apply

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of
them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before
merging your code.

• I have read the CONTRIBUTING.md
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

[github-actions]

Test results

  654 files    654 suites   4m 21s ⏱️
1 523 tests 1 521 ✅ 2 💤 0 ❌
4 569 runs  4 563 ✅ 6 💤 0 ❌

Results for commit fa374b0.

♻️ This comment has been updated with latest results.