Add build commit hash service and client helper

[jonyMarino]

Fixes: #

About

This pull request adds support for tracking and exposing the build commit hash throughout the ProjectAirSim build and runtime environment. The changes ensure that the commit hash is captured at build time, propagated into the build artifacts, and made accessible via a new service method and client API.

Build system enhancements:

• The build commit hash is captured during configuration in CMakeLists.txt using Git, with a fallback to "unknown" if unavailable. The hash is written to commit_hash.txt and displayed during configuration.
• The commit hash is passed as a compile definition (PROJECTAIRSIM_BUILD_COMMIT_HASH) to the simulator target in core_sim/src/CMakeLists.txt.
• The commit_hash.txt file is included in packaging steps for sim libs, ensuring the hash is available in distributed artifacts.

Simulator core changes:

• The Simulator::Impl class now includes a GetBuildCommitHash() method, which returns the build commit hash using the compile definition. [1] [2]
• A new service method, GetBuildCommitHash, is registered in the simulator, allowing clients to query the build commit hash at runtime.

Client API changes:

• The Python client adds a get_build_commit_hash() method, which requests the build commit hash from the simulator via the new service method.

How Has This Been Tested?

Screenshots and videos (if appropriate):