Align remote errors

[codebymini]

This PR improves error handling and user guidance for Loop APNS remote functionality.

Changes

Error Handling:

• Converted async/await methods to completion handler pattern for APNS operations
• Added HTTP status code handling (400, 403, 404, 405, 410, 413, 429, 500, 503) with specific error messages
• Implemented credential validation for APNS keys, team IDs, and device tokens
• Standardized error responses across bolus, carbs, and override operations

User Guidance:

*Added environment-specific guidance messages for APNS configuration

• Integrated build-type aware recommendations (Xcode vs Browser/TestFlight)
• Provides instructions for production environment configuration
• Shows current vs recommended environment settings

Logging:

• Removed verbose debug logging
• Streamlined logging to essential information only

[bjorkert]

Approved based on code review.

[marionbarker]

The developer who created this PR has been using it in-vivo and remotely controlling Loop.

Tested by setting up LoopFollow to follow a Loop URL. All the remote control commands continue to work as expected. Sent from iOS 18.7 phone and an iOS 16.7.11 phone to the same URL using this code for carb, bolus, override start and override cancel.