Change signatures to DerivedArtifact, and get Labels from non-Artifact sources when possible.

In tests, try to get artifacts directly from the actual configured target, rather than creating fresh ones.

This change should be a prod functional no-op, just changing signatures. Split out from the follow-up to reduce the diff.

PiperOrigin-RevId: 250527865
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java b/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java
index 1556fc2..9e82277 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java
@@ -658,8 +658,8 @@
   }
 
   /**
-   * Returns a list of actions from 'provider' that were registered by an aspect from
-   * 'aspectClasses'. All actions in 'provider' are considered - both direct and transitive.
+   * Returns a list of artifacts from 'provider' that were registered by an aspect from
+   * 'aspectClasses'. All artifacts in 'provider' are considered - both direct and transitive.
    */
   private ImmutableList<Artifact> filterTransitiveExtraActions(
       ExtraActionArtifactsProvider provider, Set<AspectClass> aspectClasses) {