pinakes-core: add plugin pipeline; impl signature verification & dependency resolution

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: Ida98135cf868db0f5a46a64b8ac562366a6a6964

crates/pinakes-core/src/plugin/registry.rs

@@ -178,8 +178,9 @@ mod tests {
           entrypoint: None,
         },
         dependencies: vec![],
+        priority: 0,
       },
-      capabilities: Default::default(),
+      capabilities: ManifestCapabilities::default(),
       config:       HashMap::new(),
     };