Add github actions

[jacobvw]

This adds github actions to perform the following jobs on pull requests:

• Runs clang-format on changed code, the action will display the patch to apply to incorrectly formatted code.
• Builds and runs tests on Ubuntu with address sanitisation.
• Builds and runs tests on MacOS with address sanitisation. The exit codes have been modified in testing scripts/applications so the gitlab runner detects the failed tests. Increases the run time on parallel tests as they were not long enough when using address sanitisation. Removed XDP from tests, the gitlab runner uses a kernel with a veth/xdp bug causing them to fail.

This also fixes a compilation issue on MacOS I introduced in the PF-RING changes

[jacobvw]

Closing this as it has been pulled into develop