Better definition of boosts, so that they are dependend on the particle ordering

[KaiHabermann]

Redefine the boosts, such that they are depending on the particle ordering for the helicity conventions

R_2 = R_1 R(pi, pi) -> the Wigner rotations correct for the transformation of phi

Also the helicity angles were given inverted up until now. This mistake was not caught due to a faulty test only checking the cosine of the angle (copied from the test against dpd, where only cosine can be tested). This will become v1.0.5

[codecov-commenter]

:warning: Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 88.08%. Comparing base (8567f92) to head (d54c1bd).

:exclamation: Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #54 +/- ## ========================================== + Coverage 88.00% 88.08% +0.07% ========================================== Files 6 6 Lines 642 646 +4 Branches 112 113 +1 ========================================== + Hits 565 569 +4 Misses 41 41 Partials 36 36 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.