Added test TribitsHelloWorld_config_git_version that uses mockprogram.py as
git to generate and check git version info.

ToDo: We should also check the generated TribitsHelloWorldRepoVersion.txt file

For some reason, mockprogram.py prints an newline that raw git does not.  But
this should work for raw git too.

Renamed the test TribitsHelloWorld_config_git_version to TribitsHelloWorld_config_git_version_single_repo_one_parent
to correctly state the scope of the test and allow for future similar tests with slightly a difference scopes
(such as single_repo_two_parents, multi_repo_one_parent, etc).

…euse (#597)

Moved git commit info functionality of tribits_generate_single_repo_version_string to
a separate helper function named tribites_generate_commit_info_string. The core functionality and
output is the same. This is in prep for reuse of that functionality inside of the original
tribits_generate_single_repo_version string.

…#597)

Removed trailing whitespace to keep git command outputs consistent with other
functions performing git commands and for the output to be more processable.

Make tribits_generate_commit_info_string output commit info based on a passed in
commit sha1.

…est (#597)

Updated mockprogram inputs and outputs to be more specific about which
commit message is being outputted.

If the HEAD sha1 contains more than one parent, include each parent's
commit info in the final repoVersionStringOut of tribits_generate_single_repo_version_string.

Forgot to double quote variable and caused configure failures during Github Actions testing.

Added global cmake cache variable `<PROJECT_NAME>_SHOW_GIT_COMMIT_PARENTS:BOOL`
that is default to OFF. This will be a project based variable to including
parent commit info in the repo version output.

Reordered git log arguments to the expected order as well as condensed
cmake command arguments into a single line.

Instead of passing in the deferenced HEAD SHA1 to tribites_generate_commit_info_string,
simply just pass in the HEAD pointer keyword for Git to deference itself.

…tput (#597)

In the off chance that Git decides to change the output of git log -1 "--pretty=format:%p",
use a regex match and replace in cmake to match consecutive spaces and replace them with a
single ;.

Simplified foreach loop in tribits_generate_single_repo_version_string and changed
the parent indexing to be 1-based instead of 0-based.

Implemented usage of previously added global cmake variable,
`PROJECT_NAME_SHOW_GIT_COMMIT_PARENTS` in `tribits_generate_single_repo_version_string`.

This is done with an optional argument named INCLUDE_COMMIT_PARENTS whenever
calling `tribits_generate_single_repo_version_string`

With Clean Code ordering (i.e. the Newspaper Metaphor), in general, the
functions should be ordered from top-level to low-level in the calling order.
That is, the functions that are called in a given function should be listed
below that function.

Cleaned up empty lines in `TribitsHelloWorld_Tests.cmake`

This allows the calling code to be more compact.  Since this function is not
really called by any external users (perhaps ever), this seems like a good
trade-off.

…HANDLING_ONLY=ON (#597)

This spead up these tests on my machine 'crf450' from about 3.4 sec to about
0.45 sec.

We don't need to enable the compilers and process the package CMakeLists.txt
files to test this version info.

This is a variable that project developers and users should know about.

…up (#597)

Using camelCase for local vars helps to differentiate from UPPER_CACHE vars for
function argument keywords and global vars.

I figured I would clean this function up while I was working on it.

Now this fits in one screen-shot for me.

…utils/ (#597)

I noticed that this module does not depend on the TriBITS framework in any way
so it should live under the core/utils/ directory to make that clear and to
allow easy reuse in non-TriBITS projects that would like to use it.

…IT_COMMIT_PARENTS (#597)

We eventually need to use this for all of those vars to make that code more
compact.

…aintainers guide (#597)

I noticed this while looking at the documentation while working on #597.

#597)

This sets the option:

  -DTribitsExMetaProj_SHOW_GIT_COMMIT_PARENTS=ON

in the inner CMake configuration with a multi-repo setup so we can test the
extraction and printing of the parent commit info.  This tests a call of the
function tribits_generate_single_repo_version_string() for extra repos from
the function tribits_generate_repo_version_file_string().  This test also
validates that the correct Git commands are called since this uses real Git on
a Git repos.

The downside of this updated test is that it makes it a little more difficult
to maintain these tests when we have to update these snapshotted Git repos.

…fo-rab

Should be final commits for Git version parent info PR #598 (#597)