Add a mustache based generator and java template (PR port) #74

Job	Run time
test-typescript-sdk-r4 (latest)	14s
test-typescript-ccda-example (latest)	25s
test-mustache-java-r4-example (latest, 25)	1m 8s
test-mustache-java-r4-example (latest, 21)	1m 8s
test-csharp-sdk (latest, 8.0.x)	1m 25s
	4m 20s

Provide feedback