lammpsdatawrite prevent scaling of LJ unit charges

[jaclark5]

Describe the behavior you would like added to mBuild
When running a simulation with LJ units and an implicit solvent, it is convenient for the charges to remain unit charges so that the dielectric constant can be derived from the Gaussian unit form of the Bjerrum length equation instead of the real unit form. In the former case, the scaling of charges will be lumped into the dielectric constant that describes the implicit solvent and require less unit conversion steps in determining this quantity.

Describe the solution you'd like
Include a charge_conversion_factor == True/False option to turn off the scaling.