WIP: Resolve "add options for altering DG formulation in local operator"

What does this MR do?

• Rework local operator to support different kinds of DG schemes, upwinding schemes, and turning weighting on and off.
• Add option to change these settings via the config file:
  • can be enabled via -DEXPERIMENTAL_DG_FEATURES=On
• Change default upwinding scheme to none

Is there something that needs to be double checked?

• Pipeline status

Can this MR be accepted?

• Builds passing

Related issues

Closes #43 (closed)