(Closes #3506) added fparser ref detection to util script + cleanup

[haanahfrost]

This PR extends the manual reference checker in the utils folder check_closed_issue_refs.py (follow up from #3556) to catch references to closed issues in the fparser directory.
Now after running the audit these are the final issues which need cleaning up:

Needs removal:

• [PSyIR] translate the algorithm layer to PSyIR #753 (PSyclone) missed in the previous PR. Issue #3506
• Separate Directives and Comments. fparser#468 (fparser) is closed and needs cleanup
• (#Closes 468) Added Directive node separated from comments fparser#469 (fparser) is closed and needs cleanup

Needs changes:

• character strings include quotes fparser#295 (fparser2) flags on the audit due to the comment format being:
  # fparser2 (issue #295) so the regex does not catch this as an fparser issue. Instead of changing the regex (which would be risky and may lead to false positives), would it be better to change the comment format to #TODO fparser #295 and standardise these practices when adding todos in the future?

Accepted formats:

• fparser #295
• fparser#295
• fparser/#295
• fparser issue #295

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (c17997a) to head (8fc1b74).
⚠️ Report is 12 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff            @@
##            master     #3561   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          397       397           
  Lines        55775     55775           
=========================================
  Hits         55775     55775           

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[sergisiso]

Thanks @haanahfrost for addressing the last reported issues:

• I agree with the fix to 111.

• The remaining 753 should be replaced with 1618

• For fparser 174, 295 and 469, I would prefer if you restored the previous version of utils/check_closed_issue_refs.py and instead replaced the references to fparser issues with full urls. For example instead of fparser #295, use https://github.com/stfc/fparser/issues/295

[sergisiso]

All good now, thanks @haanahfrost