chore: Add Git information compile-time info to only one file

[mathbunnyru]

High Level Overview of Change

Previous approach had one big flaw:

• The git commit info (GIT_COMMIT_HASH and GIT_BRANCH) is added to every file which is being compiled (https://github.com/search?q=repo%3AXRPLF%2Frippled%20add_definitions&type=code)
• It probably stopped ccache completely from working on Windows (will check this after this PR is merged)
• And made it work worse on non-Windows (cache was taken after pre-processor, which also takes time, and not directly).

I also introduce change of behaviour: we require git to be installed, and to build with git information available. It just makes life easier, because reduces number of cases we need to support.

Instead, I added a separate C++ file, where these compile-time variables are propagated and removed all other usages by using functions.
These fixes problems mentioned above.

Note: this PR doesn't change how these variables are calculated.

Context of Change

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Refactor (non-breaking change that only restructures code)
• Performance (increase or change in throughput and/or latency)
• Tests (you added tests for code that already exists, or your new feature included in this PR)
• Documentation update
• Chore (no impact to binary, e.g. .gitignore, formatting, dropping support for older tooling)
• Release

API Impact

• Public API: New feature (new methods and/or new fields)
• Public API: Breaking change (in general, breaking changes should only impact the next api_version)
• libxrpl change (any change that may affect libxrpl or dependents of libxrpl)
• Peer protocol change (must be backward compatible or bump the peer protocol version)

[godexsoft]

[ximinez]

I don't like requiring git, and requiring the repo to be checked out. It seems unnecessarily restrictive to not support building from the source in a zip file, for example. There are places on Github where one can easily do that: Release pages, the "<> Code" button on the main page, etc. There's no reason to lock those options out.

[codecov]

Codecov Report

❌ Patch coverage is 93.10345% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 79.8%. Comparing base (595f0dd) to head (f1562e2).
⚠️ Report is 1 commits behind head on develop.

Files with missing lines	Patch %	Lines
src/xrpld/app/main/Main.cpp	0.0%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##           develop   #6464     +/-   ##
=========================================
- Coverage     79.8%   79.8%   -0.0%     
=========================================
  Files          858     859      +1     
  Lines        67766   67785     +19     
  Branches      7549    7556      +7     
=========================================
+ Hits         54091   54094      +3     
- Misses       13675   13691     +16     

Files with missing lines	Coverage Δ
include/xrpl/beast/core/SemanticVersion.h	100.0% <ø> (ø)
src/libxrpl/beast/core/SemanticVersion.cpp	93.1% <100.0%> (ø)
src/libxrpl/git/Git.cpp	100.0% <100.0%> (ø)
src/libxrpl/protocol/BuildInfo.cpp	98.4% <100.0%> (+0.3%)	⬆️
src/xrpld/app/misc/NetworkOPs.cpp	70.2% <100.0%> (+0.1%)	⬆️
src/xrpld/app/main/Main.cpp	77.8% <0.0%> (ø)

... and 7 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[godexsoft]

[ximinez]

Thanks for making the changes. This looks great! I can't wait for those faster builds...