bp2build converter for cc libraries containing yacc

For cc_libraries containing .y/.yy srcs, we will generate an additional
cc_yacc_static_library target. This target will produce an .a file that
will be statically linked to the parent target.

Test: go test ./bp2build
Bug: 281546029
Change-Id: I094ba56f0a95869e5bc1e1d38b83c777192b7ddd