Read Apple required-reason codes from the docs JSON termList

To check privacy-manifest reason codes, fetch Apple's docs as JSON: https://developer.apple.com/tutorials/data/documentation/bundleresources/app-privacy-configuration/nsprivacyaccessedapitypes/nsprivacyaccessedapitype.json. Each category's reasons are a termList whose items pair a term (the code) with a definition. A regex over the raw text puts one reason's description next to the next code and makes a wrong code look right, so parse the term/definition pairs. For Disk Space (for example volumeAvailableCapacityForImportantUsageKey), E174.1 covers checking for room before writing or downloading, and 85F4.1 covers showing free space to the person. An app that refuses a download when space is short and also shows free space on a screen needs both reasons.