Xfields

**Changes**
- Introduce fast slicer based on shared memory for BB3D.
- Improvements in beamstrahlung and Bhabha

**Full Changelog**: https://github.com/xsuite/xfields/compare/v0.14.0...v0.14.1

**Changes:**
- Introduce strong-strong mode in `BeamBeamBiGaussian2D`.
- Better testing for strong-strong beam beam (including pipeline).
- Fix in `spacecharge_config_tools`

**Full Changelog**: https://github.com/xsuite/xfields/compare/v0.13.1...v0.14.0

**Changes:**
- Remove pointers to functions (not supported by pyopencl)

**Full Changelog**: https://github.com/xsuite/xfields/compare/v0.13.0...v0.13.1

**Changes:**
- Introduce Bhabha scattering effect in `BeamBeamBiGaussian3D` element.
- Introduce luminosity logging in `BeamBeamBiGaussian3D` element.
- Introduce effect of `px` `py` of the strong beam in `BeamBeamBiGaussian3D` element.

**Full Changelog**: https://github.com/xsuite/xfields/compare/v0.12.2...v0.13.0

**Changes:**
- Remove non-ascii characters for C source code

**Changes:**
- Adapt to modifications in xtrack.

**Full Changelog**: https://github.com/xsuite/xfields/compare/v0.12.0...v0.12.1