Small performance improvements

[juliasloan25]

Minor issues found in https://github.com/CliMA/ClimaCoupler.jl/issues/390 that we want to clean up for better performance.

### Tasks
- [ ] don't pass FT as an argument
- [ ] wrap `pi` in FT for calculations
- [ ] use `zero(FT)` instead of `FT(0)` to reduce allocations
- [ ] remove use of `parent` (except where needed when spaces aren't identical ?)
- [ ] make sure no closures over global variables (e.g. `FT`
- [ ] limit use of `Val` to only when necessary

some points taken from https://github.com/CliMA/ClimaCoupler.jl/issues/323