Localizations and segments data is missing in the headless page response

[Prokyonn]

Actual Behavior

The headless StructureResolver does not use the ParameterResolver, therefore data like e.g. localizations or segments is missing in the response.

Expected Behavior

StructureResolver should be extended to also add the localizations / segments to the structureData

[alexander-schranz]

This is related to #70, #100, #101 we need decide for some.kind of extension interface and how to optin this data.