feat: Add KnownCaipNamespacedChainId type

[MajorLift]

This commit adds a type for CAIP chain IDs that are namespaced by a known CAIP namespace.

This type enables the usage of safer literal string types for namespaced CAIP chain IDs, and is intended as a narrower alternative to CaipChainId.

Any and all suggestions about type name, jsdoc comments etc. are welcome.

[mcmire]

Makes sense to me.

Would be curious to know what @ccharly, @jiexi, and @erwolff think, since they worked on these types in the past.

[erwolff]

Makes sense to me.

Would be curious to know what @ccharly, @jiexi, and @erwolff think, since they worked on these types in the past.

I'll defer to @ccharly for final say here, but I think this is a useful addition. That being said, I think the reasoning (and the jsdoc comment) may need to be adjusted. 'eip155:${string}' is indeed assignable to '${string}:${string}', as it is a valid subtype. This proposed change is simply adding a narrower subtype, to ensure the namespace of the chain id is known to this library. I'd propose updating the jsdoc to something along the lines of:

/**
 * A CAIP-2 chain ID that is guaranteed to have a known CAIP namespace
 * (see {@link KnownCaipNamespace}).
 *
 * This is a narrower, more type-safe alternative to {@link CaipChainId} for use cases
 * where the chain namespace must be one of the known standards.
 */

[MajorLift]

`eip155:${string}` is indeed assignable to `${string}:${string}`

@erwolff Thanks for the correction. I should have verified that first. Looks like I was misunderstanding the error message I was seeing.

Fixed jsdoc as suggested: 23c99b9

[ccharly]

Sorry, completely miss the notification here. But that sounds like a good addition to me yes! Thanks 💪