Feature/angle conversions

[Jammy2211]

Updates the autogalaxy.convert package with the following additional checks:

• When ell_comps of a mass profile or light are converted to an angle, the angle must be between -45.0 and 135.0 degrees without a loop at the boundaries.

• When gamma_1 and gamma_2 of a shear are converted to a shear angle, the angle must be between -45.0 and 135.0 degrees without a loop at the boundaries.

• When multipole_comps are converted to phi_m, the multipole angle, it must be between values which again removing a boundary loop.

All checks ensure that when these values are computed to estimate their errors from a non-linear search, the estimation does not cycle around a boudnary and bias the inferred value.

This PR also adds docstrings.

Thank you @samlange04 for doing the hard work of figuring out the required conversions!