feat: added authenticated user storage

[dovydas55]

Note

Medium Risk
Adds a new client SDK that makes authenticated fetch calls using bearer tokens and performs runtime response validation; incorrect endpoint/config or validation could break consumers but changes are largely additive and isolated to a new package.

Overview
Introduces a new @metamask/authenticated-user-storage package that provides an AuthenticatedUserStorage TypeScript client for the Authenticated User Storage API, with namespaced accessors for delegations (list, create, revoke) and notification preferences (getNotifications, putNotifications) using optional X-Client-Type headers.

The SDK includes environment-based URL selection (Env), runtime response validation via @metamask/superstruct, standardized AuthenticatedUserStorageError wrapping, and a full Jest test suite with nock fixtures. Monorepo wiring is updated to build/typecheck the new package (tsconfig references), add ownership mappings (CODEOWNERS, teams.json), and include the workspace dependency in yarn.lock.

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[Prithpal-Sooriya]

q - do we only support EVM?

Wondering if we can change the format to use CAIP-19 to support non-evm? That way we could remove chainId and tokenAddress and just have 1 field for assetId.

[dovydas55]

@V00D00-child what do you think? i believe cash accounts team already implemted they v1. However we could look into using CAIP-10

[V00D00-child]

do we only support EVM

Yes, the Delegation Framework is only supported on EVM, so I think we should leave out using CAIP-19 for these types

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