Move pymca fitter service to python-zocalo

[pblowey]

The pymca fitter zocalo service is used for automated analysis of X-ray fluorescence (XRF) experiments. Prior to this PR, it has existed in its own repository python-zocalo-pymca. This PR migrates the code from the standalone repository, to include it in python-zocalo with other, non-mx specific, services:

• Migrate the pymca_fitter.py zocalo service file to the services directory
• Migrate the "internals.py" file in the original directory to pymca_fitter.py in the utils directory of this repository.

Some changes are also made to the pymca fitter code after migration, as detailed below:

• Remove automated email notifications sent out by the service.
• Call gnuplot from the path instead of a specific location

[pblowey]

Still unsure of how to add the new xraylib and pymca dependencies. In testing, ran into issues having the dependencies listed in the pyproject.toml file, which I suspect is due to issues installing these dependencies from pip instead of from conda-forge. The required 4.1.4 version of xraylib is not available on PyPI and is only available from conda-forge.

[ndevenish]

I assume that now you have gotten the repo working separately, that you don't need to do this?

[pblowey]

Yeah, we can close this now. Code has been kept in the python-zocalo-pymca repository.