fs: honor encoding option in glob APIs

[jorgitin02]

Summary

• honor encoding for fs.globSync(), fs.glob(), and fsPromises.glob() so encoding: 'buffer' returns Buffer paths and Buffer dirent names with withFileTypes
• avoid mutating cached dirents by cloning at output conversion boundaries
• add regression coverage for buffer parity, invalid encoding, absolute-pattern behavior, and document the option/return types (including async iterator buffer output)

Testing

• python3 tools/test.py test/parallel/test-fs-glob.mjs test/parallel/test-fs-glob-throw.mjs test/parallel/test-fs-readdir-buffer.js test/parallel/test-fs-readdir-types.js

#59202.

[jorgitin02]

Compact update: this addresses the #59202 review blockers (no cached-dirent mutation, YAML metadata added, invalid-encoding + absolute-pattern tests).