[Task]: Create AMReX versions of {zonal, meridional}_flux_thickness()

[johnmauff]

What needs to be done?

Create an AMReX implementation and the necessary shim and bridge code for {zonal, meridional}_flux_thickness()

How do we know it's done?

• A PR has been accepted & applied to the TIM repository that implements the *_flux_thickness.
• A PR has been accepted & applied to the MOM6 repository that implements the *_flux_thickness.
• A PR has been accepted & applied to the turbo-stack that uses the above TIM and MOM6 modifications

Additional info