Staged and active Standalone Prices achieved general availability status

After collecting feedback during the beta phase, we have moved the staged and active fields on StandalonePrice out of beta. The status of the following features has been changed to general availability:

• staged and active fields on StandalonePrice.
• active field on StandalonePriceDraft.
• staged field on Change Value update action.
• Apply Staged Changes and Change Active update actions.
• Standalone Price Value Changed, Standalone Price Active Changed, and Standalone Price Staged Changes Applied Messages.