[ENHANCEMENT] Inter and intramolecular components of the DCSF and CCF

**Is your feature request related to a problem? Please describe.**
Currently in MDANSE, the PDF, SSF, and the distinct part of the van Hove functions split their results into inter- and intra-molecular components. Given that the intermediate scattering function, dynamic coherent structure factor, and current correlation functions are related, we should also allow these to be split up into inter and intramolecular components.

**Describe the solution you'd like**
Similar outputs to the PDF, SSF, and the distinct part of the van Hove function so that there are inter, intra, and total results.

**Additional context**
See Section 2.5 of Principles of Neutron Scattering from Condensed Matter for equations and other details.

Start by comparing how the PDF, SSF, and distinct van Hove analyses produce inter-, intra-, and total results. Read Section 2.5 of Principles of Neutron Scattering from Condensed Matter for the equations, then apply the resulting design to the intermediate scattering function, dynamic coherent structure factor, and current correlation functions. Done means each provides inter, intra, and total outputs.

Written by the indexing model from the issue text.