App-store-server-library

- Incorporate changes for App Store Server API v1.12 and App Store Server Notifications v2.12 [https://github.com/apple/app-store-server-library-java/pull/103]
- Handle null appAccountToken appropriately in PromotionalOfferSignatureCreator [https://github.com/apple/app-store-server-library-java/pull/100]

- Incorporate changes for App Store Server API v1.11 and App Store Server Notifications v2.11 [https://github.com/apple/app-store-server-library-java/pull/94]
- Add proxy authenticator support [https://github.com/apple/app-store-server-library-java/pull/93]
- Various documentation and quality of life improvements, including contributions from hakusai22

- Incorporate changes for App Store Server API v1.10.1 [https://github.com/apple/app-store-server-library-java/pull/77]
- This change is a breaking change, as the datatype of the price field has changed from Integer to Long

- Incorporate changes for App Store Server API v1.15 and App Store Server Notifications v2.15 [https://github.com/apple/app-store-server-library-python/pull/134]

- Update the SignedDataVerifier to cache verified certificate chains, improving performance [https://github.com/apple/app-store-server-library-python/pull/122]

- Update README to improve Dependabot link discovery [https://github.com/apple/app-store-server-library-python/pull/119]