Add a script to get subscribed and onboarded laconicd accounts (#22)

Part of [laconicd testnet validator enrollment](cerc-io/testnet-laconicd-stack#19)

The script:
- Fetches onboarded participants using the configured laconicd GQL endpoint
- Reads a given CSV file with subscribers data
- Fetches all the onboarding txs using given laconicd RPC endpoint
- For each subscriber registered as a participant, maps the laconic pubkey and latest onboarding tx height
- Outputs the result in a CSV

Co-authored-by: Nabarun <nabarun@deepstacksoft.com>
Reviewed-on: cerc-io/testnet-laconicd-stack#22
Co-authored-by: Prathamesh Musale <prathamesh.musale0@gmail.com>
Co-committed-by: Prathamesh Musale <prathamesh.musale0@gmail.com>

scripts/.env.example

@@ -0,0 +1,8 @@
+# Default: https://laconicd.laconic.com/api
+LACONICD_GQL_ENDPOINT=
+
+# Default: https://laconicd.laconic.com
+LACONICD_RPC_ENDPOINT=
+
+# Default: laconic_9000-1
+LACONICD_CHAIN_ID=