ENH: Implemented Rotation.from_davenport and Rotation.as_davenport #17728

This is a follow-up to #17392. Also, this might be a bit niche, so a big part of this post is to see if there is any interest to it.
 
Davenport angles are a generalization of Euler angles.

Implemented the function `Rotation.as_davenport`, and for convenience, an inverse function called `Rotation.from_davenport` that makes internal calls to `Rotation.from_rotvec` but using the same type of parameters as `Rotation.as_davenport`. 

- Additional information:

Not any generalization is possible, basically we must have `dot(n1, n2) = dot(n2, n3) = 0`, like in Euler angles.
Moreover, for Euler angles: `dot(n1, n3) = 0, 1` or `-1`. For Davenport angles, this last can be any value between `-1` and `1` instead. Source: https://doi.org/10.1007/BF03546304.

This is a follow-up to my implementation of a new algorithm for `Rotation.as_euler()` (based on https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0276302). I now implemented a slightly modified version of the same algorithm to compute the Davenport angles for a set of input axes in the function.

In this implementation, there may be some set differences between the angles computed for the same axes by `Rotation.as_davenport` and `Rotation.as_euler` for some asymmetrical cases, but these different angles represent the same final rotation.
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