Remove expandable function

[cjrace]

Is your feature request related to a problem? Please describe.
This served us well though hasn't tested well, and DAC raised a couple of issues. Design-wise we should ditch it from the template and try to simplify the user selection area

Describe the solution you'd like
Expandable is removed, and the well panel colour is changed to a more subtle light grey or white / removed altogether.

Describe alternatives you've considered
None

Additional context
None