Firedrake Wave: use base scale as series for weak scaling
Firedrake advection-diffusion: access data read-only rather than force evaluation
Firedrake Cahn-Hilliard: access data read-only rather than force evaluation
Firedrake common: access data read-only rather than force evaluation
Firedrake Navier-Stokes: access data read-only rather than force evaluation
Firedrake Poisson: access data read-only rather than force evaluation