[ZER-502] Setup the testsuite

[mdasilva4]

This PR setups the testsuite for ur-registry library including:

• Run cppunit unit tests
• Run static code analysis
• Use exclusively standard library in the unit tests
• Setup Github Actions

[linear]

ZER-502 UR Registry - Move unit tests to separate repo and set up CI

Description

Migrate existing unit tests related to the UR Registry from wallet-gui to the new standalone repo. Set up a basic CI pipeline (GitHub Actions) to handle:

• Linting (cppcheck and flawfinder)
• Building for testing program
• Running tests

Currently the tests in the new repos can be executed by running:

./autogen.sh
./configure
make check

---

Definition of done ✅

• Unit tests: replace QByteArray and QString with std::vector<uint8_t> and std::string using standard library functions
• Unit tests are running successfully when executing make test
• Static code analyzers are running successfully when executing make test
• GitHub actions are configured and passing (build, lint, test)