IMRPhenomPv2_NRTidal

[nihargupte-ph]

Implementation of the NRTidal correction to the already implemented IMRPhenomPv2 waveform model. This was for use in (https://arxiv.org/html/2407.09602v1). Note this is NRTidalv1 not NRTidalv2.

New files
🦓 waveforms/IMRPhenomPv2_NRTidal.py
This file contains the implementation of the waveform model analogous to
waveforms/IMRPhenomD_NRTidalv2.py. I tried to avoid code duplication as
much as possible, but I didn't want to touch IMRPhenomPv2.py so there is some
duplication at the beginning of gen_IMRPhenomPv2_NRTidal. Should this be
changed?

🦓 notebooks/check_IMRPv2_NRT.ipynb
Following Thibeau's earlier PR, this file shows how one can call the waveform
model and checks that the taper, phase correction, and polarizations agree with
lalsimulation

Let me know if there is anything else which should be implemented.

[ThibeauWouters]

This is awesome, Nihar, thanks a lot! I will check the code in detail over the next few days and merge if it looks OK.