fix: Added scalar_param method to MapdlInProcess class

[valallansys]

Description

Add scalar_param method following dev to call PostProcessing

Issue linked

#4145

Checklist

• I have visited and read Develop PyMAPDL.
• I have tested my changes locally
• I have added necessary documentation or updated existing documentation.
• I have followed the PyMAPDL coding style guidelines.
• I have added appropriate unit tests that also ensure the minimal coverage criteria.
• I have reviewed my changes before submitting this pull request.
• I have linked the issue or issues that are solved to the PR if any.
• I have assigned this PR to myself.
• I have marked this PR as draft if it is not ready to be reviewed yet.
• I have made sure that the title of my PR follows Commit naming conventions (e.g. feat: adding new MAPDL command)

[codecov]

Codecov Report

❌ Patch coverage is 16.66667% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 91.34%. Comparing base (de1cf18) to head (b8fe089).
⚠️ Report is 1 commits behind head on main.

❌ Your patch status has failed because the patch coverage (16.66%) is below the target coverage (90.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4161      +/-   ##
==========================================
+ Coverage   91.31%   91.34%   +0.02%     
==========================================
  Files         193      193              
  Lines       15724    15730       +6     
==========================================
+ Hits        14358    14368      +10     
+ Misses       1366     1362       -4     

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[germa89]

@valallansys

We link PR/Issues with #, no !.

Soo.. it is #4145

[germa89]

Please do move that method to mapdl_core.py as stated in my comment.

[germa89]

This PR is now on hold while we figure out the problem with the CLA bot.

Once @Revathyvenugopal162 or @jorgepiloto approves it, we can merge.

In the meantime, @valallansys you can work on this PR as normal. If you need to merge this fast, contact me.

[ansys-cla-bot]

⚠️ CLA Check Failed: Unable to identify commit authors

This pull request contains commits where the author information is missing or invalid. This typically happens when:

• A user has changed their GitHub username
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