feat: allow data insert in mocker

[Caele]

Motivation

Experimental setup to allow non-engine rendering of Nebula charts.
Example:

const mockedApp = await __DO_NOT_USE__.EnigmaMocker.fromGenericObjects();

const nebbie = embed(mockedApp, {
  types,
  context: {
    constraints: {
      select: true,
    },
  },
});

const hyper = hypercube({
    numRows: rowData.length,
    dimensions: [
      {
        value: (f, i) => rowData[i][0],
        override: {
          ...
        },
      },
    ],
    measures: [
      {
        value: (f, i) => rowData[i][1],
        override: {
          ...
        },
      },
    ],
  });

 nebbie.render({
    type: 'bar',
    element,
    properties: {
      _mock: {
        qHyperCubeDef: null,
        qHyperCube: hyper,
      },
    },
  });
}