Improve git commit hash lookup

[ximinez]

High Level Overview of Change

Changes the lookup of the git hash included in rippled's version number (for debug builds) to use rev-parse instead of describe, plus a few more improvements.

• Also get the branch name.
• Return the git hash and branch name in server_info for admin connections.
• Include git hash and branch name on separate lines in --version.

Context of Change

Commit bf013c0 back in 2021 used git describe to find the hash of the commit being built when building rippled.

From the description of git describe:

The command finds the most recent tag that is reachable from a commit. If the tag points to the commit, then only the tag is shown. Otherwise, it suffixes the tag name with the number of additional commits on top of the tagged object and the abbreviated object name of the most recent commit. The result is a "human-readable" object name which can also be used to identify the commit to other git commands.

This sometimes results in rippled version numbers that look like:

rippled version 2.4.0-b1+ppe-build-175-g49e0d54c76be6323f7932386973e38b490e18eda.DEBUG

We want version numbers that look like:

rippled version 2.4.0-b1+49e0d54c76be6323f7932386973e38b490e18eda.DEBUG

In other words, without ppe-build-175-g, indicating that the commit is 175 commits after the ppe-build tag, particularly since that tag is on version 2.1.0-rc1 from February.

This changes the lookup to use git rev-parse instead, which always just returns a hash.

While I was in there, I also added code to find the branch name, and included the hash and branch name in the admin-only result of server_info, and the output of --version, so this info can be found on release builds as well.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Tests (you added tests for code that already exists, or your new feature included in this PR)

API Impact

• Public API: New feature (new methods and/or new fields)

Before / After

rippled --version

Before:

rippled --version on a debug build may return something like

rippled version 2.4.0-b1+ppe-build-175-g49e0d54c76be6323f7932386973e38b490e18eda.DEBUG

After:

rippled --version on a debug build will return something like

rippled version 2.4.0-b1+c14acfc32b3375427405372d742b5b72f3c430dc.DEBUG
Git commit hash: c14acfc32b3375427405372d742b5b72f3c430dc
Git build branch: pr/gch

And on a release build will return something like

rippled version 2.4.0-b1
Git commit hash: c14acfc32b3375427405372d742b5b72f3c430dc
Git build branch: pr/gch

server_info

Before:

server_info does not include any git information.

After:

server_info on an admin connection will include git info:

  [...]
  "complete_ledgers": "92826571-92837212",
  "git": {
    "branch": "pr/gch",
    "hash": "c14acfc32b3375427405372d742b5b72f3c430dc"
  },
  "hostid": "HOST",
  [...]

[codecov]

Codecov Report

Attention: Patch coverage is 60.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 78.1%. Comparing base (33e1c42) to head (36dcee2).
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   #5225   +/-   ##
=======================================
  Coverage     78.1%   78.1%           
=======================================
  Files          790     790           
  Lines        67556   67562    +6     
  Branches      8158    8159    +1     
=======================================
+ Hits         52785   52790    +5     
- Misses       14771   14772    +1     

Files with missing lines	Coverage Δ
src/xrpld/app/misc/NetworkOPs.cpp	70.2% <100.0%> (+<0.1%)	⬆️
src/xrpld/app/main/Main.cpp	79.0% <0.0%> (-0.8%)	⬇️

... and 2 files with indirect coverage changes

[legleux]

I love it

[godexsoft]

Clio could add these too in the future. No objection from our side.

[ximinez]

The commit message from the first commit (plus PR #) is good to use for the merge.