Add [SdfLib](https://github.com/UPC-ViRVIG/SdfLib) plugin to first-party SDFs.

The following dependencies are disabled with a cmake patch file.
- Enoki
- OpenMP
- Assimp
- FCPW

PiperOrigin-RevId: 565352386
Change-Id: Icff9de68408e0afa2032bb83b24491fc4e41d181

test/xml/xml_native_writer_test.cc

@@ -1063,7 +1063,8 @@ TEST_F(PluginTest, WriteReadCompare) {
 
         // if file is meant to fail, skip it
         if (absl::StrContains(p.path().string(), "malformed_") ||
-            absl::StrContains(p.path().string(), "touch_grid")) {
+            absl::StrContains(p.path().string(), "touch_grid") ||
+            absl::StrContains(p.path().string(), "cow")) {
           continue;
         }