feat: adding context manager to MapdlPool

[germa89]

As the title

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[codecov-commenter]

Codecov Report

Attention: Patch coverage is 27.58621% with 21 lines in your changes are missing coverage. Please review.

Project coverage is 81.02%. Comparing base (5442a4e) to head (0224d9f).
Report is 3 commits behind head on main.

❗ Current head 0224d9f differs from pull request most recent head 108f7ba. Consider uploading reports for the commit 108f7ba to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3047      +/-   ##
==========================================
- Coverage   86.63%   81.02%   -5.62%     
==========================================
  Files          52       52              
  Lines        9498     9525      +27     
==========================================
- Hits         8229     7718     -511     
- Misses       1269     1807     +538     

[clatapie]

LGTM!