Added diffusion reset in hydro when doing feedback and updated function signatures

We need to also reset the diffusion to zero when doing feedback as well as resetting the viscosity to max.

I have:

• Done this for schemes that include variable diffusion
• Re-named the function to hydro_diffusive_feedback_reset as this no longer only resets the viscosity

changed the description

added 1 commit

• 8f4d7fbe - Fixed incorrectly named variables

Compare with previous version

merged

mentioned in commit 0c86a0ae