Update examples that reference context Population

[brynrhodes]

The Chlamydia Screening CQM example (and potentially others) still reference context Population. These should be updated to reference Unspecified context.

[JohannesOehm]

Maybe one could also add some examples that use the FHIR data model as baseline and not only QUICK and QDM.

[JPercival]

Just to clarify, this issue applies only to the 1.4 release of the CQL translator. 1.3 still requires context Population.

[JPercival]

This is an issue contributing to #1314