Handle downloaded template sets with missing source jars

[jan-vcapgemini]

The TemplateAdapterImpl can detect template set jars which don't provide a source jar.
We need to add an exception handling and maybe automatically download missing source jars if needed.

cobigen/cobigen/cobigen-core/src/main/java/com/devonfw/cobigen/impl/adapter/TemplateAdapterImpl.java

Lines 256 to 262 in 28f53b0

	templateSetJars.removeAll(resultJars);
	if (!templateSetJars.isEmpty()) {
	for (Path jarWithMissingSource : templateSetJars) {
	LOG.error("Missing Source for Jar: " + jarWithMissingSource.getFileName());
	// no matching source file found either download or handle somehow
	// TODO throw Exception or download the missing source
	}