function processState(instance) {
  const type = instance.type;
  const props = type.props;
  const getters = type.vuex && type.vuex.getters;
  const computedDefs = type.computed;
  const data = { ...instance.data,
    ...instance.renderContext
  };
  return Object.keys(data).filter(key => !(props && key in props) && !(getters && key in getters) && !(computedDefs && key in computedDefs)).map(key => ({
    key,
    type: 'data',
    value: (0, util_2.returnError)(() => data[key]),
    editable: true
  }));
}
Process state, filtering out props and "clean" the result
with a JSON dance. This removes functions which can cause
errors during structured clone used by window.postMessage.

@param {Vue} instance
@return {Array}