feat(NewtonsoftJson): Upconvert from Case that should be a string

Provide an upconversion that lets you write the updated form per `TypeSafeEnumConverter`, but also accept mangled versions that predate impl of #96

i.e. read:
```
"items": [
{
"serviceId": "5c8795be52e34e82883d61babed19513",
"serviceKind": {
"Case": "ProductA"
}
},
{
"serviceId": "8a55ebbf0d404485b50da95bdb53f7b3",
"serviceKind": {
"Case": "ProductB"
}
}
]
},
```
but write:
```
"items": [
{
"serviceId": "5c8795be52e34e82883d61babed19513",
"serviceKind": "ProductB"
},
{
"serviceId": "8a55ebbf0d404485b50da95bdb53f7b3",
"serviceKind": "ProductA"
}
]
```
related: https://github.com/JamesNK/Newtonsoft.Json/issues/1662#issuecomment-1646777848