Archetype: add support for conditional blocks #491

Job	Run time
shellcheck	34s
checkstyle	45s
copyright	41s
build	2m 38s
spotbugs	4m 58s
javadoc	1m 59s
cli/linux-amd64	3m 10s
tests/cli-linux	2m 31s
cli/windows-amd64	5m 23s
tests/cli-windows	4m 57s
vscode-extension	1m 23s
cli/darwin-amd64	7m 15s
tests/cli-functional-linux	4m 50s
tests/cli-functional-windows	5m 41s
tests/archetype-linux	2m 40s
tests/archetype-windows	5m 18s
tests/linker-linux	3m 14s
tests/linker-windows	4m 34s
tests/misc-linux	3m 21s
tests/misc-windows	5m 20s
	1h 11m 12s

Provide feedback