Refactored all the opeations tests.
* Decreased tolerance for float type tests to work with `float32_t`, `float64_t` and `floatmax_t`
* Changed tests where `int` types are required to work with both `int` and `float`
* Did not add `complex128_t`, `bool` or `char` tests

I added the SE test whilst there is no fix for the typed test for this case (see my PR description)

* get_epsilon is called inside each test case to determine the tolerance
* tested these values with my own machine
* solver tests will have a lower threshold, as these seem to change quite a bit depending on machine and lapack/blas installations
* if typed testing is rolled out for all unit tests should move this to its own header file

* solvers have a fixed threshold
* also fixed indentation