Avoids unnecessary allocations

[canadacubachina]

Fix #731

[sarahelsaig]

In LoginInfoJsonConverter the instance is registered in code (see here).
The created Instance variables here are not actually used.

[infofromca]

In LoginInfoJsonConverter the instance is registered in code (see here). The created Instance variables here are not actually used.

As a lib or nuget, we can create it for the extensible for other custom module to extend by registration and DI

[sarahelsaig]

As a lib or nuget, we can create it for the extensible for other custom module to extend by registration and DI

That's not useful. You should never have to use these converters directly, because are tied to the converted class using an attribute: [JsonConverter(typeof(AmountConverter))].

If for some reason you still need an instance of the converter, you can create a static instance in your own code. Adding these static properties here would only be confusing for everyone else.