Unify object generation and serialization approaches

[kMutagene]

The overall strategy for creating objects to serialize and serve via the dash app endpoints should be the same everywhere:

• When it is a object with no optional fields:

  -> Record type with [<JsonProperty>] attribute indicating the correct json property name

• When it is an object with optional fields:

  -> class inheriting from DynamicObj using the init(and optionally style/applyMembers pattern, see Optional component record fields #29)

• When it is an enum:

  DU with the following static members: toString (which converts to the correct string for the js enum), and convert, which boxes the result of toString see for example here:
  

  Dash.NET/src/Dash.NET/DashComponents/ComponentBase.fs

  Lines 41 to 61 in f869c10

  	type InputType =
  	| Text
  	| Number
  	| Password
  	| Email
  	| Range
  	| Search
  	| Tel
  	| Url
  	| Hidden
  	static member toString = function
  	| Text -> "text"
  	| Number -> "number"
  	| Password -> "password"
  	| Email -> "email"
  	| Range -> "range"
  	| Search -> "search"
  	| Tel -> "tel"
  	| Url -> "url"
  	| Hidden -> "hidden"
  	static member convert = InputType.toString >> box