refactor: Iterate over the dictionary directly instead of using .keys().

[MaxJPRey]

Description

• Iterate over the dictionary directly instead of using .keys().
  If you want to check whether a specific key is in a dictionary, you can write if key in dictionary. There's no need to write if key in dictionary.keys(). Furthermore, if key in dictionary is faster because it uses a hash lookup, while if key in dictionary.keys() generates a new list and then does a linear search through that list.

• Remove some bare except.

• Update some docstrings.

Issue linked

Please mention the issue number or describe the problem this pull request addresses.

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)

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[codecov]

Codecov Report

Attention: Patch coverage is 66.66667% with 1 line in your changes missing coverage. Please review.

Project coverage is 87.14%. Comparing base (4f75f6a) to head (32e50de).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3631      +/-   ##
==========================================
- Coverage   87.18%   87.14%   -0.05%     
==========================================
  Files         187      187              
  Lines       14660    14660              
==========================================
- Hits        12781    12775       -6     
- Misses       1879     1885       +6