Passpredict

A major update.

Use Satellogic's [orbit-predictor](https://github.com/satellogic/orbit-predictor) library as the basis for prediction algorithm, coordinate transformations, locations, propagators, and tle sources. The algorithms are supplemented with custom Cython functions and IAU SOFA routines for speed. Remove unused custom cpp code for now.

Improve test suite by adding observation tests using a new brute force observer class to compute predicted passes. Validate visual passes against Heaven's Above.

Improve the CLI output using [rich](https://github.com/Textualize/rich) tables.

Implemented basic cache system with built-in python `shelve` module

- Added module level entrypoint to CLI. Can be invoked with `python -m passpredict`
- Added color output to CLI
- Added hotfix for arcsin bounds error

test github action

ISS overpass list generally agrees with Heaven's Above. Still need to compute satellite visibility and add documentation.