Improvement: Switch chain based configuration of controllers to pallet based configuration

[filvecchiato]

Proposed Change or Idea

While working on a new controller, it seems like it could be beneficial to move away from a chain based configuration (src/chains-config) to instead inject the required controllers of sidecar depending on the pallets detected from the chain metadata. More than one controller could be configured for a pallet, and overrides could be available for specific chains, as well as base controllers available for any given chain.

This method would maintain the current dep-injection of controllers in express, but instead of having a list of chains with the required controllers, it would remove the need to create new configuration files for new chains created, instead being mostly supported out of the box by checking the chain's metadata.