Bring up to date with v3

[elisachisari]

CCL is now almost at v3. We should make sure the notebooks follow the new API. These ones need checking:

• Angular cross-correlations.ipynb
• Halo-model-Pk.ipynb
• Baryons_halo_model_power_spectrum.ipynb
• MCMC Likelihood Analysis.ipynb
• CalculatorMode.ipynb
• MG_mu_Sigma_with_z_and_k_dependences.ipynb
• CellsCorrelations.ipynb
• MG_mu_Sigma_with_z_dependence_only.ipynb
• Distance Calculations Example.ipynb
• MG_mu_sigma_examples.ipynb
• GeneralizedTracers.ipynb
• PerturbationTheoryPk.ipynb
• Halo profiles.ipynb
• Power spectrum example.ipynb
• Halo-mass-function-example.ipynb
• Reading-writing-Cosmology-objects.ipynb

Do any new functionalities need to be identified?

[nikosarcevic]

sounds like a plan!
I know a few typos here and there and will be looking into this.

regarding the functionalities in ccl per se, I personally think that we might want to reconsider how hmcode is called now. I am not sure if this is being discussed with the wonderful folk who work on cclv3 but I think how we have it now is not so user friendly.

for other functionalities in the notebooks, I will have to think about it