Introducing pattern and length validation for keys of Embedded Prices and Standalone Prices

As we have recently introduced a key field on Embedded Prices, we have aligned pattern and length constraints accordingly so that there are no inconsistencies for imported Prices.

Values for the key field in EmbeddedPriceDraftImport, EmbeddedPriceImport, and StandalonePriceImport should now match the pattern ^[A-Za-z0-9_-]+$ and be 2-256 characters in length. The key value will be validated when processing import requests with the following objects:

• Product draft import endpoints having Price keys.
• StandalonePriceImport on Importing Standalone Prices.
• EmbeddedPriceImport on Importing Embedded Prices.