Add generic regridding function to XESMF.jl

[simone-silvestri]

I was thinking we could also add a generic regridding function to this package, since we have already src_temp and dst_temp.

In this way, we can avoid the dependency on LinearAlgebra in our extensions

[navidcy]

And then we should be calling eg this method on every k index?

[simone-silvestri]

Yeah, I think so. Maybe we can investigate how to do a batched matrix multiply, for example NNlib.batched_mul.