test: correcting test_scan_multiline with respect to rpm parser

[tahifahimi]

This PR considers that the RPM parser is added based on #2964. (so, first that PR should be merged and then this request)
PR #2964 fails due to inconsistency in the test for testing multiline capability in file test/test_helper_script.py. This PR applies changes to extract_and_parse_file functionality in file cve_bin_tool/helper_script.py to reuse the multiple tests.
Other details are in #3845

Close #2916

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 5 lines in your changes are missing coverage. Please review.

Project coverage is 78.71%. Comparing base (d6cbe40) to head (7822202).
Report is 38 commits behind head on main.

Files	Patch %	Lines
cve_bin_tool/helper_script.py	0.00%	4 Missing ⚠️
test/test_helper_script.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3870      +/-   ##
==========================================
+ Coverage   75.41%   78.71%   +3.30%     
==========================================
  Files         808      807       -1     
  Lines       11983    11963      -20     
  Branches     1598     1401     -197     
==========================================
+ Hits         9037     9417     +380     
+ Misses       2593     2114     -479     
- Partials      353      432      +79     

Flag	Coverage Δ
longtests	?
win-longtests	78.71% <0.00%> (?)

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