Release 1.1.0

Changes since 1.0.0:
- Upgraded project toolchain to Java 21 and modern Gradle, including wrapper refreshes.
- Added JaCoCo coverage support and Makefile coverage/build workflow improvements.
- Improved HTTP client handling and build configuration reliability.
- Fixed multiple test and build issues (including null key handling and failing tests).
- Updated documentation, examples, and package/version references across README and demo.

SerpApi wrapper for Java in version 1.0.0