Support for testnet

[vikiival]

Describe the feature

I would like to have a testing env for KodaDot so we can test features more effortlessly.
This indexer would be based on the Paseo testnet

Expected outcome

• paseo.json with defined stuff
• typegen for paseo testnet
• snack.yml for deploy

Reference

Seems assethub is missing, pinged people

[yangwao]

If it could be paid off the treasury, it can be done

[vikiival]