Handle missing costs and quantities

[flanakin]

🛠️ Description

Address new data quality issues with data ingested into Data Explorer:

• Fix x_EffectiveUnitPrice when it's calculated and there is a rounding error compared to x_BilledUnitPrice or ContractedUnitPrice.
• Calculate PricingQuantity and ConsumedQuantity when there is cost but no quantity.
• Set ListCost based on ContractedCost or ListUnitPrice when not specified.
• Replaced "-2" and "Unassigned" values in the x_InvoiceSectionId and x_InvoiceSectionName columns.
• Corrected x_EffectiveUnitPrice when it's calculated and has a rounding error.
• Add new x_SourceChanges checks for "MissingConsumedQuantity", "MissingPricingQuantity", and "XEffectiveUnitPriceRoundingError".

Related to #1111

📋 Checklist

🔬 How did you test this change?

• 🤏 Lint tests
• 🤞 PS -WhatIf / az validate
• 👍 Manually deployed + verified
• 💪 Unit tests
• 🙌 Integration tests

🙋‍♀️ Do any of the following that apply?

• 🚨 This is a breaking change.
• 🤏 The change is less than 20 lines of code.

📑 Did you update docs/changelog.md?

• ✅ Updated changelog (required for dev PRs)
• ➡️ Will add log in a future PR (feature branch PRs only)
• ❎ Log not needed (small/internal change)

📖 Did you update documentation?

• ✅ Public docs in docs (required for dev)
• ✅ Internal dev docs in src (required for dev)
• ➡️ Will add docs in a future PR (feature branch PRs only)
• ❎ Docs not needed (small/internal change)