Fetch program with resource requests if exists (#122)

`Database.find_program(..)` is used e.g. in program manager, which
depends on embedded program resource requests, if such are configured.

Old version of this method didn't fetch them along the program data, so
the method is now a wrapper for `get_program(..)` but handles error as
non-existing program.

crates/node/src/storage/database/postgres.rs

@@ -69,11 +69,11 @@ impl Database {
     }
 
     pub async fn find_program(&self, hash: impl AsRef<Hash>) -> Result<Option<Program>> {
-        // non-macro query_as used because of sqlx limitations with enums.
-        let program = sqlx::query_as::<_, Program>("SELECT * FROM program WHERE hash = $1")
-            .bind(hash.as_ref())
-            .fetch_optional(&self.pool)
-            .await?;
+        let mut conn = self.pool.acquire().await?;
+        let program = match self.get_program(&mut conn, hash).await {
+            Ok(program) => Some(program),
+            Err(_) => None,
+        };
 
         Ok(program)
     }