aba_payway

• Rename getMerchantByRegisterRef to inquiryMerchantByRef and update associated response models for consistency.
• Implement inquiryMerchantByKey and ABAInquiryMerchantByKeyRequestModel to support credential inquiries via existing merchant keys.
• Remove the unused merchantId parameter from ABAPayway and ApiService initializers.
• Refactor opensslEncrypt to accept String inputs instead of Map, ensuring proper JSON encoding before encryption.
• Update generateHash utility to use publicKey as the HMAC key instead of partnerId.
• Expand the example application and README.md to demonstrate new registration and inquiry flows.
• Bump package version to 0.0.1-beta.2 and update CHANGELOG.md.

✨ New Features

• Added support for configuring existing API keys with inquiryMerchantByKey.
• Introduced ABAInquiryMerchantByKeyRequestModel for API key inquiry requests.

🛠️ Refactoring & Improvements

• Renamed getMerchantByRegisterRef to inquiryMerchantByRef.
• Renamed ABAGetMerchantResponseModel to ABAInquiryMerchantResponseModel and updated associated models.
• Removed unused merchantId parameter from ABAPayway and ApiService initializers.
• Updated opensslEncrypt helper function to accept a String instead of Map<String, dynamic>.
• Updated generateHash to accept publicKey instead of partnerId for HMAC key generation.

🐛 Bug Fixes

• Fixed openssl encryption logic to JSON-encode requests properly before encryption.

📝 Documentation & Examples

• Updated README.md with new inquiryMerchantByRef and inquiryMerchantByKey integration steps.
• Updated the example app (example/lib/main.dart) to demonstrate registration status and API key credential inquiry.

✨ New Features

• Initial release for partner integration