Add PTYCHO_tomoParameters

Reported by @cloetens

In the hdf5_cfg.xml file we would have something along the lines (in bold what I would like to add):

${PTYCHO_propagation} ${PTYCHO_beamSize} ${PTYCHO_stepSize} ${PTYCHO_focusToDetectorDistance} ${PTYCHO_countTime} ${PTYCHO_parameters} ${PTYCHO_tomoParameters}

 <refN record="final" ESRF_description="Ptycho parameters" NAPItype="NX_FLOAT">${PTYCHO_refN}</refN>
  <darkN record="final" ESRF_description="Ptycho parameters" NAPItype="NX_FLOAT">${PTYCHO_darkN}</darkN>
  <pixelSize record="final" ESRF_description="Ptycho parameters" NAPItype="NX_CHAR" units="micron">${PTYCHO_pixelSize}</pixelSize>
  <group NX_class="NXcollection" groupName="Axis1">
     <name ESRF_description="Scan motor in the horizontal direction" NAPItype="NX_CHAR">${PTYCHO_Axis1_name}</name>
     <range ESRF_description="Range of the moves in microns" NAPItype="NX_FLOAT" units="micron">${PTYCHO_Axis1_range}</range>
  </group>
  <group NX_class="NXcollection" groupName="Axis2">
     <name ESRF_description="Scan motor in the horizontal direction" NAPItype="NX_CHAR">${PTYCHO_Axis2_name}</name>
     <range ESRF_description="Range of the moves in microns" NAPItype="NX_FLOAT" units="micron">${PTYCHO_Axis2_range}</range>
  </group>