Add CI for build and tests

[BewareMyPower]

See:

• https://github.com/apache/pulsar/blob/master/.github/workflows/ci-cpp-build.yaml
• https://github.com/apache/pulsar/blob/0f53c790ff2e3051ebc80aa8d2c9253265725aeb/.github/workflows/pulsar-ci.yaml#L480-L482

[yaalsn]

@BewareMyPower @merlimat I'll add this workflow.

[BewareMyPower]

Thanks @yaalsn, I assigned it to you.

[merlimat]

Sorry, I didn't see this one. I added one PR to start addressing this: #14