Feat/add stellar bridge controller

[Julink-eth]

Explanation

Adds Stellar support to @metamask/bridge-controller, following the existing non-EVM patterns for Solana, Bitcoin, and Tron. This includes Stellar chain/native asset constants, CAIP formatting, default token metadata, quote validation, non-EVM fee handling via snap computeFee, and targeted test coverage.
Also aligns Stellar asset formatting with the Bridge API contract:

• Native XLM: stellar:pubnet/slip44:148
• Classic assets: stellar:pubnet/asset:CODE-ISSUER
• Soroban contracts: stellar:pubnet/sep41:C...

References

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

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Note

Medium Risk
Introduces a new non‑EVM chain path (chainId/assetId formatting and quote validation), which could affect quote fetching/validation across supported chains if mappings are incorrect.

Overview
Adds Stellar (XLM pubnet) as a supported non‑EVM chain for @metamask/bridge-controller, including new ChainId.STELLAR, updated allowed chain lists/ranking, and native token metadata (symbol/decimals + SLIP-44 mapping).

Extends bridge/CAIP utilities to recognize Stellar chainIds (isStellarChainId, inclusion in isNonEvmChainId), convert Stellar chainIds to CAIP (stellar:pubnet), and format Stellar asset IDs for classic assets (asset:CODE-ISSUER) and Soroban contracts (sep41:C...). Quote request validation is tightened to require destWalletAddress when bridging to or from Stellar, and tests are added/updated to cover Stellar fee computation via Snap computeFee and the new formatting/feature-flag scenarios.

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