- selectMyChannelClaims depends on `byId`, which currently is always invalidated per update, so it is not memoized.
- Most of the use-cases just needs the ID or the length of the array anyways, so avoid generating a Claim array (in selectMyChannelClaims) unnecessarily -- the client need to reduce it back down to IDs again :/
- The simpler boolean also removes the need to memoize the selector, which saves a bit of memory.
