Chigoe Family Improvements

[jmcmorris]

I affirm:

• [x] I understand that if I do not agree to the following points by completing the checkboxes my PR will be ignored.
• [x] I understand I should leave resolving conversations to the LandSandBoat team so that reviewers won't miss what was said.
• [x] I have read and understood the Contributing Guide and the Code of Conduct.
• [x] I have tested my code and the things my code has changed since the last commit in the PR and will test after any later commits.

What does this pull request do?

This fixes a few things with chigoes.

1. Add additional effects to Chigoes
2. Use correct mixin for some Chigoe NMs
3. Remove file for mob that doesn't exist - Tunga in Aydeewa Subterrane

Steps to test these changes

1. Go to a chigoe !gotoid 17100900 and get hit some and you'll receive Disease effect eventually (10% chance)
2. Changed NMs (Tunga and Chelicerata) will no longer die from critical hits, weapon skills, or certain job abilities