Store presence data inside `ChannelProvider`'s context, so we don't have to refetch presence data for every listener

[VeskeR]

See PR comment https://github.com/ably/ably-js/pull/1674#discussion_r1517565591. See code in question from usePresence hook (or usePresenceListener after https://github.com/ably/ably-js/pull/1674 is merged): https://github.com/ably/ably-js/blob/integration/v2/src/platform/react-hooks/src/hooks/usePresence.ts#L41C1-L51C58

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