bp2build: Refactor CreateBazelTargetModule API.

This CL refactors the CreateBazelTargetModule API to minimize boilerplate, and to establish a well defined function signature for the expected metadata about a BazelTargetModule.

Test: soong tests

Test: TH
Change-Id: I474ff5a2b0db8deeed49ba4ca73b416ccb494fdd
diff --git a/bazel/properties.go b/bazel/properties.go
index 5b98d15..fbbbfe6 100644
--- a/bazel/properties.go
+++ b/bazel/properties.go
@@ -29,6 +29,8 @@
 // BazelTargetModuleProperties contain properties and metadata used for
 // Blueprint to BUILD file conversion.
 type BazelTargetModuleProperties struct {
+	Name *string
+
 	// The Bazel rule class for this target.
 	Rule_class string