Allow setting default parameter view to expression rather than evaluation

[jeffglitchless]

Right now, I believe the only way to tell if a parameter is driven by an expression rather than a plain value, you have to either hold shift and mouseover to wait for the advanced popup, or right click and actually edit the expression. Some of us would rather see the expression by default, and perhaps the evaluation to leading it.

For a super-simple compromise: just some sort of graphical indicator like a superscript e at the top right of the parameter box to at least let us know that a parameter is expression-based would be great.

Thanks!