Resolver context type - subtype can be optional

[vejrj]

Newly accept optional parameter

  {
     baseContextTypePath: "@package/default-context",
      baseContextTypeName: "DefaultContextType",
      contextTypes: {
        managers: {
          user: {
            importNamespaceName: "UserStateMachineType",
            importPath: "@package/user-state-machine",
            typeName: 'UserStateMachineType["user"]',
          },
          optionalWhatever: {
            importPath: "@package/whatever-state-machine",
            typeName: "optionalWhatever",
            optional: true,
          },
} }