Use peerDependency or some other way to decouple parachain project type dependency from txwrapper

[xlc]

I created a simple dependency diagram: https://dreampuf.github.io/GraphvizOnline/#digraph%20G%20%7B%0A%20%20%20%20app%20-%3E%20txwrapper_acala%0A%20%20%20%20txwrapper_acala%20-%3E%20txwrapper_core%0A%20%20%20%20txwrapper_acala%20-%3E%20txwrapper_registry%0A%20%20%20%20txwrapper_registry%20-%3E%20apps_config%0A%20%20%20%20apps_config%20-%3E%20acala_js%0A%20%20%20%20apps_config%20-%3E%20polkadot_js%0A%7D

As you can see, when acala introduce new types, we will update acala.js, and then apps-config needs update then txwrapper-registry needs update, wxwrapper-acala needs update. This will take time definitely doesn't scale.

Acala can maintain txwrapper-acala but we will still depends on txwrapper-registry

Should have a way to allow user of txwrapper to specify the parachain project type / npm package without requiring update all the intermediate dependencies

[emostov]

Yes, I definitely agree with this idea. To build on it, I think dependance on txwrapper-registry should be avoided when possible because it will require waiting for a cascade of package updates as you clearly point out. Instead we should direct txwrapper maintainers to define their own getRegistry and import their chain specific type package directly.

This should be resolved by #45.

Below is a very rough example of how that may work

// `getRegistry` implementation for a hypothetical txwrapper for a frame based chain.
// This would mean that the txwrapper would not have to require txwrapper-registry and instead can update
// its type package directly as opposed to having to wait for apps-config to update
import { typesBundle, typeSpec, typesChain } from '@frame-based-chain/polkadot-js-types'

 // This interface could be exported from txwrapper-core
export interface GetRegistryOpts {
	/**
	 * Runtime specName
	 */
	specName: keyof typeof knownChainProperties;
	/**
	 * chainName
	 */
	chainName: string;
	/**
	 * Runtime specVersion
	 */
	specVersion: number;
	/**
	 * SCALE encoded runtime metadata as a hex string
	 */
	metadataRpc: string;
	/**
	 * Optionally specify the chain properties .
	 */
	properties?: ChainProperties;
}

export function getRegistry({
	specName,
	chainName,
	specVersion,
	metadataRpc,
	properties,
}: GetRegistryOpts): TypeRegistry {
	// Polkadot, kusama, and westend have known types in the default polkadot-js registry. If we are
	// dealing with another network, use the apps-config types to fill the registry.
	const registry = new TypeRegistry();
	registry.setKnownTypes({
		typesBundle,
		typesChain,
		typesSpec,
	});

	return getRegistryBase({
		chainProperties: properties || knownChainProperties[specName],
		// `getSpecTypes` is used to extract the chain specific types from the registries `knownTypes`
		specTypes: getSpecTypes(registry, chainName, specName, specVersion),
		metadataRpc,
	});
}