Extract BlackOilFluidState factory into general-purpose free function; drop TypeTag dependency

[Copilot]

createFluidState() was a WellInterface member function tied to well-specific state (pvtRegionIdx(), name()), making it unusable outside the well abstraction. The boolean flags controlling fluid state behaviour were also redundantly extracted from TypeTag despite being direct template parameters of BlackOilFluidState.

Changes

New: opm/simulators/utils/BlackOilFluidStateUtils.hpp

• Introduces free function createBlackOilFluidState<FluidSystem, Indices, bool...>() — usable from any context (reservoir, aquifer, etc.)
• Template parameters mirror BlackOilFluidState's own template args directly; no TypeTag required; blackoilproperties.hh / EnergyModuleType.hpp not needed
• pvtRegionIdx and name are explicit parameters; auto return type avoids repeating the BlackOilFluidState specialisation twice
• setTemperature guarded by enableTemperature (not just enableEnergy) — correct for ConstantTemperature and SequentialImplicitThermal modes too

// Before: TypeTag-coupled, well-only
template <typename TypeTag, typename ValueType>
auto createBlackOilFluidState(...);  // extracts FluidSystem, Indices, flags from TypeTag

// After: self-contained, no TypeTag
template <class FluidSystem, class Indices,
          bool enableTemperature, bool enableEnergy,
          bool enableEvaporation, bool enableBrine,
          bool enableSaltPrecipitation, bool enableDisgasInWater,
          typename Scalar, typename ValueType>
auto createBlackOilFluidState(...);  // flags match BlackOilFluidState template params 1:1

Updated: opm/simulators/wells/WellInterface_impl.hpp

• createFluidState() becomes a thin wrapper passing its existing static constexpr members as explicit template arguments:

  return createBlackOilFluidState<FluidSystem, Indices,
                                   energyModuleType != EnergyModules::NoTemperature,
                                   has_energy, has_watVapor, has_brine,
                                   has_saltPrecip, has_disgas_in_water,
                                   Scalar>(fluid_composition, pressure, temperature,
                                           saltConcentration, pvtRegionIdx(), name());

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