Serialize FormulaStructs in the internal API

[Rylan12]

This is a cleaner attempt of #21429.

I've added serialize and deserialize methods to FormulaStruct to efficiently store formula data in JSON format. After the simplifications made in #21455, the code needed to accomplish this is pretty straightforward.

The goal is that the only special handling needed in FormulaStruct#serialize and FormulaStruct#deserialize is for cases where there is a simpler way to store the data than is needed by Formulary. At the moment, the only two customizations needed are:

• bottle data: only need to store the relevant checksum (and can leave information like the bottle tag, cellar, and rebuild if they are the default values)
• dependency/uses_from_macos information: deduplicate dependencies that are both stable and head deps by storing shared dependencies separately

I also added a handful of methods to Utils so they can, eventually, be used by CaskStruct. I've added tests for all of these methods.

[MikeMcQuaid]

Thanks! Good to merge when comments addressed.

[Copilot]

Pull request overview

This PR adds serialization and deserialization functionality to FormulaStruct to enable efficient JSON storage for the internal API. The implementation provides methods to convert FormulaStruct instances to/from JSON-compatible hashes, with special handling for bottle data (storing only relevant checksums and omitting default values) and comprehensive utility methods for symbol/string conversion and removing blank values.

Changes:

• Added serialize and deserialize methods to FormulaStruct with special bottle handling
• Implemented utility methods (format_arg_pair, stringify_symbol, deep_stringify_symbols, deep_unstringify_symbols, deep_compact_blank) for data transformation
• Updated generate-formula-api.rb to use the new serialization instead of the previous custom implementation
• Added tests for all new utility methods

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
Library/Homebrew/api/formula_struct.rb	Core implementation: adds serialization constants, serialize/deserialize methods, and utility methods for symbol handling and data compaction
Library/Homebrew/dev-cmd/generate-formula-api.rb	Refactored to use new serialization methods, replacing ~50 lines of custom logic with a simple serialize() call
Library/Homebrew/test/api/formula_struct_spec.rb	Added comprehensive tests for utility methods (format_arg_pair, stringify_symbol, deep_stringify_symbols, deep_unstringify_symbols, deep_compact_blank)

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[Rylan12]

Okay, assuming CI is good here, let's merge so we can get the JSON files in formulae.brew.sh, and move onto the next step

[MikeMcQuaid]

Looks good thanks! Can self-merge as-is with or without changes.