project-then-approximate hyper-reduction API

[eparish1]

Mirrors issue #135 but for project-then-approximate.

[eparish1]

def ProjectThenApproximate(list_of_function_snapshots : np.ndarray, list_of_test_basis: np.ndarray, tolerance: float, method='ECSW', **kwargs) -> np.ndarray, np.ndarray:
   
        pass