Trim redundant USE statements from Base.F90 (MAPLBase_Mod)

[tclune]

Summary

base/Base.F90 (MAPLBase_Mod) currently re-exports 26 modules via bare use statements. Many of these are defined in shared/ or base3g/ and are already available to consumers via the proper MAPL3 export path (MAPL → MaplShared or mapl_base3g). Keeping them in MAPLBase_Mod is redundant and makes the module a catch-all umbrella rather than exporting only what it owns.

Removed (11 use statements)

Module	Defined in	Already exported via
MAPL_Constants (both lines incl. MAPL_PI_R8 alias)	shared/	MaplShared → MAPL
MAPL_SortMod	shared/	MaplShared → MAPL
MAPL_SunMod	base3g/	mapl_base3g → MAPL
MAPL_InterpMod	shared/	MaplShared → MAPL
MAPL_HashMod	shared/	MaplShared → MAPL
MAPL_LoadBalanceMod	shared/	MaplShared → MAPL
MAPL_DirPathMod	shared/	MaplShared → MAPL
MAPL_KeywordEnforcerMod	shared/	MaplShared → MAPL
MAPL_SimpleCommSplitterMod	shared/	MaplShared → MAPL
MAPL_SplitCommunicatorMod	shared/	MaplShared → MAPL
mapl_LocalDisplacementEnsemble	base3g/	mapl_base3g → MAPL

Must stay (despite living in shared/ or base3g/)

Module	Reason
MAPL_ShmemMod	AppGridCreate.F90 (FVdycoreCubed) uses MAPL_AllocNodeArray and MAPL_DeAllocNodeArray transitively via use MAPL2, only: — removing broke the build
MAPL_MemUtilsMod	Same file uses MAPL_MemUtilsWrite transitively via use MAPL2, only:

These two will need to remain until their consumers (AppGridCreate.F90) are updated to use the modules directly.

What stays (only in base/)

Modules defined only in base/ (or whose removal is deferred) are unchanged:
ESMFL_Mod, MAPL_ExceptionHandling, MAPL_BaseMod, MAPL_IOMod, MAPL_ConfigMod, MAPL_LocStreamMod, MAPL_MaxMinMod, MAPL_SimpleBundleMod, MAPL_ApplicationSupport, MAPL_ServerManager, MAPL_FileMetadataUtilsMod, MAPL_VerticalDataMod, MAPL_SphericalGeometry