Phase 6: Rename gridcomps/ subdirectories (closes #4905 phase 6)

[tclune]

Summary

Phase 6 of the MAPL v3 directory & library restructuring (#4905).

Rename the gridcomps/ subdirectories from their current names to lowercase, canonical names. Must be done on a Linux host (case-sensitive filesystem).

Renames

Current	New
gridcomps/cap3g/	gridcomps/cap/
gridcomps/History3G/	gridcomps/history/
gridcomps/ExtData3G/	gridcomps/extdata/
gridcomps/StatisticsGridComp/	gridcomps/statistics/
gridcomps/Orbit/	gridcomps/orbit/

Tasks

• Rename each directory via git mv
• Update gridcomps/CMakeLists.txt add_subdirectory() calls
• Update any internal CMakeLists or source references to old directory names
• Build + test pass before merging

Parent Issue

Part of #4905