ComPWA/tensorwaves: Python fitter package for multiple computational back-ends

TensorWaves is a fitter package that optimizes mathematical models to data samples. The models can be any _symbolic_ mathematical expression that is then converted to any computational backend. In addition, TensorWaves provides functionality to generate toy Monte Carlo data samples. The package is developed in parallel with [AmpForm](https://github.com/ComPWA/ampform), which implements physics models, but its 'lambdifying' mechanisms can in principle be used independently.