Fixing various issues reported in v4.1.1

I had to make a few changes that may be incompatible with existing consumers, but they are small enough that I think this can be considered a minor version update rather than a full major version. The changes which are most likely to affect existing code are the updates to response::IdType (see changes to how the fake ID's are initialized in TodayMock.cpp), and how nullable nested input types are represented as std::unique_ptr instead of std::optional to support cycles of nullable/list input types (see changes in ClientTests.cpp where it initializes the Variables::CompleteTaskInput variable).

What's Changed

• Fixes for #208 and #209 by @wravery in #214
• Make CMake old-file cleanup safer/more specific by @wravery in #215
• Update PEGTL submodule to 3.2.5 by @wravery in #219
• Add a unit test for invalid string escape sequences by @wravery in #223
• Adds a virtual default destructor for RequestState by @ALTinners in #228
• Add a configurable depth limit to the parser by @wravery in #231
• Accept either a Base64 encoded binary or an opaque string in response::IdType by @wravery in #232
• Options to remove base64 ID encoding at compile time by @ALTinners in #229
• More constexpr schema by @wravery in #234
• More constexpr schema by @ALTinners in #227
• Input type references by @wravery in #235

New Contributors

• @ALTinners made their first contribution in #228

Full Changelog: v4.1.1...v4.2.0