PCell & CML generalization for polarization and wavelength

[lukasc-ubc]

Update all components to support TE, TM or both polarizations, for any centre wavelength, using the automated CML generation via FDTD.

Add to each component:

• pol: 'TE' or 'TM'; for use in INTERCONNECT calling FDTD to simulate one of these if pol is defined, or simulate both if undefined.
• wavelength: default 1550. Consider a simulation bandwidth of 10% of the central wavelength. Used by the INTERCONNECT-FDTD simulation.

rename components,

e.g., ebeam_y_1550 -> ebeam_y e.g., ebeam_dc_te1550 -> ebeam_dc