Support blocking nested kext plugins by Bundle ID / exact path

[YBronst]

Motivation

• Allow blocking of nested kext plugins (kexts inside other kexts) by Bundle ID or exact path because existing OpenCore/Clover bridging only matched top-level .kext paths and missed plugins such as IONetworkingFamily.kext/.../AppleEthernetRL.kext.
• Implement the resolution on the loader side since OpenCore itself does not index nested kext bundle identifiers.
• Limit recursion depth to a safe default (2) to satisfy current requirements while keeping the logic extensible.

Description

• Add depth-limited bundle-id scanning utilities and caching in rEFIt_UEFI/refit/main.cpp, introducing MAX_BUNDLE_ID_INDEX_DEPTH = 2 and KEXT_BLOCK_PATH_RESOLUTION to cache results.
• Implement NormalizeKextBundlePath, ReadKextBundleIdentifier, ResolveBundlePathInDirectory, ResolveKextBundlePath, and GetSystemKextRoot to locate a kext by its CFBundleIdentifier under \System\Library\Extensions and \Library\Extensions, including searching Contents/PlugIns and Contents/Plugins up to configured depth.
• Add ResolveKextBlockIdentifier that returns normalized exact bundle path for .kext entries and resolves bundle IDs to paths where possible, storing unresolved IDs in cache to avoid repeated scans.
• Integrate resolver into OpenCore Kernel.Block assignment so entries in KextsToBlock use resolved paths (or fall back to the original name) when building mOpenCoreConfiguration.Kernel.Block.

Testing

• Automated tests: none were run for this change.

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Codex Task