Exponential damper parameters and example

[dhblum]

The use_v_nominal, v_nominal, and A parameters in Fluid.Actuators.Dampers.Exponential can be confusing, particularly as illustrated in Examples.Damper where both A and v_nominal have values of 1.

• Propose removing parameters use_v_nominal and v_nominal, and having m_flow_nominal/rho_default/1 as the default value in A.
• Propose changing Examples.Damper to remove the specifier of A=1.

ASHRAE 825-RP gives a range of reasonable values for k0 and k1, which could be used to ensure proper damper model performance.

• Propose adding an assert statement to the values of parameters k1 and k0 to ensure they are within the range of those reported in ASHRAE 825-RP.

No tests for when the parameter linearized=True.

• Propose changing Examples.Damper by adding a damper in parallel to res with linearized=True to compare the performance.

[mwetter]

These are all good changes.

[Mathadon]

closed through #545