Refactor: Indexer building

[Tburm]

We have a folder for each chain, and each folder contains configurations to build an indexer for that chain including the ABIs and contract addresses. Each individual folder contains repetitive configurations, and utilizes a fork of the official subsquid library for generating the indexers.

The image building can be simplified by putting the configs together, and building a single image depending on the chain provided. Additionally, we should revisit the forked library for something more official.

Tasks:

• Improve build process
• Remove @troy_/squid-gen-evm dependency from indexers