Blender Git Loki

Fix T61187: Fluid Particle settings UI elements

Some properties were accidentally hidden for particle fluids.

- Made sure we show the Forces and Integration
sub-panels for particle fluids.
- Slightly re-ordered the sub-panels here, so that the same sub-panels
are at the top for Newtonian and Fluid particles.
- Separated the Fluid Interaction sub-panel so we can give it a unique
name.
- Removed lingering unnecessary 'Keys' label in the Keyed physics.