[clang][ssaf] Add JSONFormat support for WPASuite (#187403)
This patch adds `JSONFormat` serialization support for `WPASuite`.
- Adds `readWPASuite` / `writeWPASuite` to the `SerializationFormat`
abstract interface and implements them in `JSONFormat`.
- Introduces `AnalysisResultRegistryGenerator`, a per-format plugin
registry template in `SerializationFormat`, allowing analysis authors to
register (de)serializers for their `AnalysisResult` subtypes with a
single static declaration.
- Extends `PrivateFieldNames.def` with `WPASuite::Data` and
`WPASuite::IdTable`, and adds a `makeWPASuite()` factory to
`SerializationFormat`, so deserialization code can construct a
`WPASuite` incrementally through the same access-controlled pattern
used for all other SSAF data structures.