[Caip-25] make-wildcard-ban-more-explicit

[bumblefudge]

As per last two meetings of RPC WG, I made namespace-wide scope objects explicitly "ALL/only specified chains" rather than "ANY" to discourage "wildcard" semantics. (See third commit for clear delta).

First commit was just long-overdue cleanup of CAIP-25 editorially to make for cleaner deltas in this and future RPC WG PRs.

Second commit was a related normative but nonbreaking change: I realized it was never explicit that requiredScopes, optionalScopes, and sessionScopes can't have redundant keys.