nzp-team/nzportable#1194 - Fix broken Ballistic Knife assets crashing Vril on load

[MotoLegacy]

… Vril on load

Description of Changes

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Adds two new PR tests:

• PCX Validation: Affirm PCX textures have an indexed color palette and each dimension size is a power-of-two
• MDL Validation: Very intense header + vert validation to help protect against checking in broken MDL models.

Fixes the Ballistic Knife texture+model. Fixes nzp-team/nzportable#1194

Visual Sample

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Checklist

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• I have thoroughly tested my changes to the best of my ability
• I confirm I have not contributed anything that would impact Nazi Zombies: Portable's licensing and usage
• This Pull Request fixes a critical issue that should be reviewed and merged as soon as possible