InnerDetector: Separation and specialisation of strip/beam frame transformations to resolve polar annulus digitisation faliures

Previously, digitisation of endcap tracks would fail when a polar co-ordinate system was used. Additionally, errors were seen from the StripSurfaceChargeGenerator when calculating the drift distance. These problems were found to be caused by the conversion between beam and strip frames, which was generally performed in the assumption of cartesian co-ordinates.

This merge request consolidates the beam frame <--> strip frame transforms in StripStereoAnnulusDesign into their own methods, and provides polar specialisations. The other methods in StripStereoAnnulusDesign have been modified to rely on these methods, rather than applying their own transform.

Two versions of the polar specialisations of the transform are used - one which first converts the co-ordinate to cartesian, applies the transform, and then converts back to polar, and another version which works exclusively in a polar co-ordinate system. The derivations of these transforms are detailed at ATL-COM-ITK-2021-048. These will later be profiled to determine the optimal method.

This MR is part of ATLITKSW-42. @nstyles @pagessin @hhayward