Create GHA extract shell scripts action

[omus]

Implements the action. A future improvement that could be made would be to lint action.yaml files.

[github-actions]

sh-checker report

To get the full details, please check in the job output.

shellcheck errors

'shellcheck ' returned error 1 finding the following syntactical issues:

----------

In integration-tests.yaml/job=Test/step=Test_extracted.sh line 17:
echo $foo
     ^--^ SC2154 (warning): foo is referenced but not assigned.
     ^--^ SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean: 
echo "$foo"

For more information:
  https://www.shellcheck.net/wiki/SC2154 -- foo is referenced but not assigned.
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...
----------

You can address the above issues in one of three ways:
1. Manually correct the issue in the offending shell script;
2. Disable specific issues by adding the comment:
  # shellcheck disable=NNNN
above the line that contains the issue, where NNNN is the error code;
3. Add '-e NNNN' to the SHELLCHECK_OPTS setting in your .yml action file.

shfmt errors

'shfmt ' found no issues.