Some fields should be boolean instead of integer

[leendertvanwolfswinkel]

model_settings.friction_averaging
model_settings.use_2d_rain
physical_settings.use_advection_1d
physical_settings.use_advection_2d

[margrietpalm]

@leendertvanwolfswinkel model_settings.friction_averaging is a custom enum type:

friction_averaging = Column(IntegerEnum(constants.OffOrStandard))

Any specific reason to make this a bool? Because this is quite a bit of extra work compared to the other three.

[margrietpalm]

@leendertvanwolfswinkel physical_settings.use_advection_1d has several options:

use_advection_1d = Column(IntegerEnum(constants.AdvectionTypes1D))

with

class AdvectionTypes1D(Enum):
    OFF = 0
    MOMENTUM_CONSERVATIVE = 1
    ENERGY_CONSERVATIVE = 2
    COMBINED_MOMENTUM_AND_ENERGY_CONSERVATIVE = 3

I do remember changing, this but do not remember exactly why.

[leendertvanwolfswinkel]

OK I may have been a little bit too boolean-happy here...

use_advection_1d indeed has several options, so should not be converted to boolean. It is also somewhat likely that we add more options to use_advection_2d sometime in the future.

However, for model_settings.friction_averaging and model_settings.use_2d_rain I don't think we will add extra options, so imo boolean would be more suitable.