Change default scheme for HydrostaticSphericalCoriolis

[glwagner]

The default should be ActiveCellEnstrophyConserving according to @simone-silvestri

[navidcy]

you only seem to have changed the docstring function signature.
let's change the description below to agree with the signature...

and also, the constructor at the moment seems to suggests that it's actually the EnergyConserving that is the default, no?

julia> using Oceananigans

julia> HydrostaticSphericalCoriolis()
HydrostaticSphericalCoriolis
├─ rotation rate: 7.29e-05 s⁻¹ = 1.00e+00 Ω_Earth
└─ scheme: EnergyConserving{Float64}

[navidcy]

OK, some regression tests break with this change (probably because the data was produced with the default scheme which was different). Also some unit tests. I'll have a look.

[glwagner]

oh sorry

[navidcy]

No worries!
it brings up an issue that regression tests and generation scripts should not rely on default args/kwargs