Move interface so building to action configs

This cl moves the conditional building of interface libraries from LinkCommandLine to action configs and features. It provides link_dynamic_library.sh to keep blaze backwards compatible. The script and related code can be deleted once all crosstools are updated.

RELNOTES: No.

--
MOS_MIGRATED_REVID=135799041
diff --git a/tools/cpp/BUILD b/tools/cpp/BUILD
index 50d19a8..a3c8cbe 100644
--- a/tools/cpp/BUILD
+++ b/tools/cpp/BUILD
@@ -158,3 +158,8 @@
     name = "srcs",
     srcs = glob(["**"]) + ["//tools/cpp/test:srcs"],
 )
+
+filegroup(
+    name = "link_dynamic_library",
+    srcs = ["link_dynamic_library.sh"],
+)