Migrate LDE, MemUtils, SunOrbit to base3g; add FileIO and TimeInterpolation modules (#4758)

* Migrate LDE, MAPL_MemUtils, MAPL_sun_uc to base3g; add FileIO and TimeInterpolation modules

- Move LDE.F90 -> base3g/LocalDisplacementEnsemble.F90; replace MAPL_DistGridGet with ESMF_DistGridGet
- Move MAPL_MemUtils.F90 and MAPL_sun_uc.F90 to base3g; drop unused MAPL_BaseMod/MAPL_IOMod dependencies
- Add base3g/FileIO.F90 (mapl3g_FileIO) with string variant of WRITE_PARALLEL
- Add base3g/TimeInterpolation.F90 (MAPL_TimeInterpolation) with MAPL_Interp_Fac and MAPL_ClimInterpFac extracted from Base_Base
- Update base3g/API.F90 to re-export all new public symbols
- Comment out MAPL_Interp_Fac call in generic/MAPL_Generic.F90 (generic/ being retired)

* Remove MAPL_ prefix from migrated base3g source filenames

* Fix missing MAPL_ExceptionHandling use in LocalDisplacementEnsemble

* Use mapl_ErrorHandling directly instead of MAPL_ExceptionHandling wrapper in base3g

* Replace MAPL_ExceptionHandling with mapl_ErrorHandling in Comms and StringTemplate

* Fix missing use mapl3g_FileIO and MAPL_TimeInterpolation in MemUtils and SunOrbit

Author: tclune