op_store: embed details in operation/view not found error

This is basically a copy of BackendError::ObjectNotFound. The failed id may
be either view or operation id.

cli/src/cli_util.rs

@@ -1958,7 +1958,7 @@ fn resolve_single_op_from_store(
             Ok(operation) => {
                 return Ok(Operation::new(op_store.clone(), op_id, operation));
             }
-            Err(OpStoreError::NotFound) => {
+            Err(OpStoreError::ObjectNotFound { .. }) => {
                 // Fall through
             }
             Err(err) => {

lib/src/op_store.rs

@@ -384,8 +384,12 @@ content_hash! {
 
 #[derive(Debug, Error)]
 pub enum OpStoreError {
-    #[error("Operation not found")]
-    NotFound,
+    #[error("Object {hash} of type {object_type} not found: {source}")]
+    ObjectNotFound {
+        object_type: String,
+        hash: String,
+        source: Box<dyn std::error::Error + Send + Sync>,
+    },
     #[error("Error when reading object {hash} of type {object_type}: {source}")]
     ReadObject {
         object_type: String,

lib/src/simple_op_store.rs

@@ -155,7 +155,11 @@ impl OpStore for SimpleOpStore {
 
 fn io_to_read_error(err: std::io::Error, id: &impl ObjectId) -> OpStoreError {
     if err.kind() == ErrorKind::NotFound {
-        OpStoreError::NotFound
+        OpStoreError::ObjectNotFound {
+            object_type: id.object_type(),
+            hash: id.hex(),
+            source: Box::new(err),
+        }
     } else {
         OpStoreError::ReadObject {
             object_type: id.object_type(),