Extends / improves DCU functionality and tests

Adds DCA.clean_up function to enable simplified clean up of open coverages and paused streams

Adds TestSimpleDelimitedParser class with tests for parser functionality.

Minor changes to testmanualupload.yml and testcalcoeff.yml to improve test coverage of SimpleDelimitedParser

Increases coverage of DirectCoverageAccess

Improves warnings when DCA is used outside of context management and tests warnings