Improve autocompletion for lazy module

[hoxbro]

__dir__ is for IPython/Jupyter, and type checking is for LSP like Pylance.

(I am also using this PR for some unrelated clean up)

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 75.00000% with 2 lines in your changes are missing coverage. Please review.

Project coverage is 88.53%. Comparing base (fef3219) to head (2afcc02).
Report is 2 commits behind head on main.

Files	Patch %	Lines
holoviews/__init__.py	75.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6174      +/-   ##
==========================================
- Coverage   88.68%   88.53%   -0.15%     
==========================================
  Files         316      316              
  Lines       66073    66076       +3     
==========================================
- Hits        58597    58502      -95     
- Misses       7476     7574      +98     

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[github-actions]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.