Add flags for splitting path packages by top-level modules and by schema paths.

[wenovus]

Tested flag combinations with exampleoc (moved under internal), and uexampleoc.

[coveralls]

Pull Request Test Coverage Report for Build 5719310256

• 27 of 36 (75.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.2%) to 81.941%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pathgen/pathgen.go	27	36	75.0%
<!--	Total:	27	36	75.0%	-->

Totals
Change from base Build 5696407390:	-0.2%
Covered Lines:	1883
Relevant Lines:	2298

---

💛 - Coveralls