Change order for how FileDescriptors are returned in reflection service.

- FileDescriptors should be returned with the service first and then all dependencies after. All dependencies should occur after a FileDescriptor.
- See grpc/grpc-go#2949
  The Java implementation of the reflection service includes the entire transitive closure for a request file, in toplogical order such that a file's dependencies always appear after the file (so the requested file is first, with all of its dependencies after it).

src/protobuf-net.Grpc.Reflection/ReflectionService.cs

@@ -153,19 +153,19 @@ public int Compare(FileDescriptorProto? left, FileDescriptorProto? right)
             {
                 if (left is null)
                 {
-                    return right is null ? 0 : -1;
+                    return right is null ? 0 : 1;
                 }
                 if (right is null)
                 {
-                    return 1;
+                    return -1;
                 }
                 if (GetTransitiveDependencies(left).Contains(right.Name))
                 {
-                    return 1;
+                    return -1;
                 }
                 if (GetTransitiveDependencies(right).Contains(left.Name))
                 {
-                    return -1;
+                    return 1;
                 }
 
                 return string.Compare(left.Name, right.Name, StringComparison.Ordinal);

tests/protobuf-net.Grpc.Reflection.Test/ReflectionServiceTests.cs

@@ -74,9 +74,9 @@ async IAsyncEnumerable<ServerReflectionRequest> GetRequest()
                 ".ReflectionTest.BclService",
                 new[]
                 {
+                    "ReflectionTest.BclService.proto",
                     "google/protobuf/empty.proto",
-                    "protobuf-net/bcl.proto",
-                    "ReflectionTest.BclService.proto"
+                    "protobuf-net/bcl.proto"
                 }
                 ,
                 new[]