Support images as well as indexes in ImageDetailResolvers (#183)

* build: Generate test data for unsigned and no provenance image indexes
* feat: Add function to build index without SBOM or provenance for linux/amd64 platform
* feat: add build_image function to build image without SBOM or provenance for linux/amd64
* feat: Rename NO_SBOM_NO_PROVENANCE_INDEX_DIR to UNSIGNED_IMAGE_DIR
* feat: support images in details resolvers

test/testdata/unsigned-index/index.json

@@ -0,0 +1,14 @@
+{
+    "schemaVersion": 2,
+    "manifests": [
+        {
+            "mediaType": "application/vnd.oci.image.index.v1+json",
+            "digest": "sha256:db8f2a6e112ea6396f57d073269ecfac61e8dcdad3a4a643dcb577522492f898",
+            "size": 1607,
+            "annotations": {
+                "org.opencontainers.image.created": "2024-04-29T10:23:46Z",
+                "org.opencontainers.image.ref.name": "docker.io/library/test-image:test"
+            }
+        }
+    ]
+}