Updates for stage2 setup (#60)

Part of [Create a public laconicd testnet](https://www.notion.so/Create-a-public-laconicd-testnet-896a11bdd8094eff8f1b49c0be0ca3b8)

- Add `bc` installation in Dockerfile (required for stage1 to stage2 testnet migration)
- Populate attributes map index when importing records from genesis to allow fetching records with filters from a chain with imported state

Reviewed-on: cerc-io/laconicd#60
Co-authored-by: Prathamesh Musale <prathamesh.musale0@gmail.com>
Co-committed-by: Prathamesh Musale <prathamesh.musale0@gmail.com>

Dockerfile

@@ -19,7 +19,7 @@ FROM ubuntu:22.04
 # Install ca-certificates, jq, curl, bash, and other necessary packages
 RUN apt-get update && apt-get install -y --no-install-recommends \
     ca-certificates \
-    jq curl netcat bash \
+    jq curl netcat bash bc \
     && rm -rf /var/lib/apt/lists/*
 
 # Copy over binary from the builder