Fix SafeJsonSerializer

[alexyakunin]

https://github.com/servicetitan/Stl/blob/master/src/Stl/Serialization/SafeJsonNetSerializer.cs

Currently it "solves" two problems:

1. Safe denationalization - the Verifier delegate is used on deserialization to tell if the root type is fine to deserialize, and this piece is totally ok to keep
2. But overall, it doesn't allow to serialize everything b/c it serializes only the top level type name, so anything nested that needs a type (e.g. Exception) won't deserialize.

#2 works the way it does to actually address the issue w/ WASM: mscorlib is named differently there, so this serializer "fixes" this issue by normalizing its name - and it can do this nicely only b/c there is a single place it needs to fix (root type name).

The right fix, though, would be to fix mscorlib name everywhere during the serialization. Not sure how to do this w/ JSON.NET, but pretty sure it's possible. And if this is done, the serializer would be a complete fit for Stl.Fusion needs:

• Safe deserialization will be used there on "update request" end (Publisher, etc.) - the types should be limited just to a few message types there, the rest should be banned.
• And no-filter deserialization will be used on "update/invalidate receiver" end (i.e. WASM client), where it's totally safe to desalinize everything (it's still a browser-sandboxed .NET).

[alexyakunin]

Just closed this one.