[epilogue] Support logging of protobuf-serializable types (#8229)

For parity with struct-serializable types.

Change struct serialization to only apply to types with a public static final <type> struct field, instead of relying only on the marker interface (which is not always followed). Doing this allows fallthrough to the protobuf handler for types with dynamic structs but static protobuf serializers.

epilogue-runtime/src/test/java/edu/wpi/first/epilogue/logging/LazyBackendTest.java

@@ -8,6 +8,7 @@ import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertSame;
 
+import edu.wpi.first.math.geometry.Rotation2d;
 import java.util.List;
 import org.junit.jupiter.api.Test;
 
@@ -185,4 +186,17 @@ class LazyBackendTest {
     assertArrayEquals(
         new byte[] {0x01, 0x00, 0x00, 0x00}, (byte[]) backend.getEntries().get(1).value());
   }
+
+  @Test
+  void lazyProtobuf() {
+    var backend = new TestBackend();
+    var lazy = new LazyBackend(backend);
+
+    var rotation = Rotation2d.kZero;
+    lazy.log("rotation", rotation, Rotation2d.proto);
+    assertEquals(1, backend.getEntries().size());
+    var entry = backend.getEntries().get(0);
+    assertEquals("rotation", entry.identifier());
+    assertArrayEquals(new byte[] {9, 0, 0, 0, 0, 0, 0, 0, 0}, (byte[]) entry.value());
+  }
 }

epilogue-runtime/src/test/java/edu/wpi/first/epilogue/logging/TestBackend.java

@@ -4,12 +4,14 @@
 
 package edu.wpi.first.epilogue.logging;
 
+import edu.wpi.first.util.protobuf.Protobuf;
 import edu.wpi.first.util.struct.Struct;
 import edu.wpi.first.util.struct.StructBuffer;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import us.hebi.quickbuf.ProtoMessage;
 
 @SuppressWarnings("PMD.TestClassWithoutTestCases") // This is not a test class!
 public class TestBackend implements EpilogueBackend {
@@ -114,4 +116,12 @@ public class TestBackend implements EpilogueBackend {
 
     m_entries.add(new LogEntry<>(identifier, serialized));
   }
+
+  @Override
+  public <P, M extends ProtoMessage<M>> void log(String identifier, P value, Protobuf<P, M> proto) {
+    var msg = proto.createMessage();
+    proto.pack(msg, value);
+    var serialized = msg.toByteArray();
+    m_entries.add(new LogEntry<>(identifier, serialized));
+  }
 }