Add SonarCloud configuration

[andrablaj]

Describe the improvement you'd like Add a file containing the repo-level SonarCloud configuration for cht-conf.

Similar to https://github.com/medic/cht-interoperability/pull/112.

You can find related documentation here.

[andrablaj]

@sugat009 I opened this ticket, in case you want to dig into how the SonarCloud setup works and set it up for this repo.

[sugat009]

Closing, as this has already been done through https://github.com/medic/cht-conf/pull/618