Merge XPNR branch into lalsuite master

Detailed Description

This merge request adds the new waveform spin-precessing, quasi-circular approximant IMRPhenomXPNR. IMRPhenomXPNR is an updated waveform model for quasi-circular, spin-precessing binary black-hole systems based on the IMRPhenomX framework. This model combines the improvements to the co-precessing frame modes and NR-calibrated merger-ringdown Euler angles introduced in IMRPhenomXO4a with the more accurate description of inspiral Euler angles introduced in IMRPhenomXPHM_SpinTaylor. Code changes have undergone extensive testing during the review process. We have verified that the new model works as intended and none of the changes modify earlier versions of PhenomX models.

API Changes

Please tick one of the following options:

• These changes do not modify the API.
• These changes do modify the API, and are backwards compatible.
• These changes do modify the API, and are backwards incompatible.

Review Status

The code has been signed off. More details on the review, including the final review statement, can be found on the review wiki page. The review was performed by Hector Estelles (chair), Lorenzo Pompili, Shaun Swain, Thibeau Wouters and Jannik Mielke, with Eleanor Hamilton, Marta Colleoni and Jonathan Thompson as the core reviewees.