Scope GRPC/ODB/OpenVDS/HDF5 build flags to avoid full rebuilds

[magnesj]

Summary

Toggling RESINSIGHT_ENABLE_GRPC, RESINSIGHT_USE_ODB_API, RESINSIGHT_ENABLE_OPENVDS, or the HDF5 detection result currently forces a full rebuild of the entire project (ThirdParty, VizFwk, and all caf* frameworks), even though none of that code references these macros.

Root cause

The root CMakeLists.txt used directory-scoped �dd_definitions() for USE_ODB_API and ENABLE_GRPC before most �dd_subdirectory() calls, so toggling either flag changed the compiler command line for essentially every target in the build.

Fix

• Phase 1: Removed the two global �dd_definitions() calls from the root CMakeLists.txt. Replaced them with arget_compile_definitions() on the actual consumer targets (ApplicationLibCode, ApplicationExeCode, Commands, GeoMechDataModel, GrpcInterface).
• Phase 2: Further narrowed USE_OPENVDS / USE_HDF5 / ENABLE_GRPC / USE_ODB_API to set_source_files_properties() on the small set of files that actually reference each macro, so toggling a flag only recompiles a handful of files instead of the whole monolithic ApplicationLibCode/Commands targets.
• Also removed the unused SOURCE_GROUP_HEADER_FILES variable from GrpcInterface/CMakeLists.txt (dead code, no effect on the build).

Verification

• Full build succeeded with the existing config (GRPC=ON, OpenVDS=ON, HDF5=ON).
• Verified via �uild.ninja inspection that ThirdParty/VizFwk/caf* targets no longer reference ENABLE_GRPC/USE_ODB_API.
• Verified toggling RESINSIGHT_ENABLE_GRPC OFF: uncovered and fixed a pre-existing, unrelated Qt AUTOMOC caching bug (stale mocs_compilation.cpp referencing a conditionally-excluded header) that required clearing the ResInsight_autogen cache; full build then succeeded (28/28) with GRPC off.
• ODB toggle-off itself was not build-tested in this environment (ODB SDK not configured here), but the CMake logic was verified via configure success and code review.

Marked as draft pending final review/testing.