Ensure ad and cart service do not generate errors by default

[flands]

Changes

Addresses #1628 and adds variability to errors for cart service

Merge Requirements

For new features contributions please make sure you have completed the following
essential items:

• CHANGELOG.md updated to document new feature additions
• Appropriate documentation updates in the [docs][]
• Appropriate Helm chart updates in the [helm-charts][]

[flands]

Hmm, while this works, it generates an error: flagd | 2024-06-30T14:41:30.614Z error evaluator/fractional.go:30 parse fractional evaluation data: percentages must sum to 100, got: 110 {"component": "evaluator", "evaluator": "json"} will revisit this.