Fix skeleton templates

[roomrys]

Description

In #1265 while moving the dock creation logic outside the MainWindow class, a critical line was overlooked: https://github.com/talmolab/sleap/blob/0e7a3725d5e238b97f5daa35795829a15cd156db/sleap/gui/commands.py#L1955

The MainWindow.skeletonTemplates attribute was renamed to MainWindow.skeleton_dock.skeleton_templates, but this line (untested due to its GUI nature) was left behind.

This PR corrects the line above to correctly call the Video_Dock.skeleton_templates attribute. While we do not test the OpenSkeleton.ask method where the error originated from, this PR moves the code used to get the filename to a staticmethod on the OpenSkeleton class which is called in the docks tests. The code has also been manually tested to run through the OpenSkeleton.ask method and works as expected.

Types of changes

• [x] Bugfix
• [ ] New feature
• [ ] Refactor / Code style update (no logical changes)
• [ ] Build / CI changes
• [ ] Documentation Update
• [ ] Other (explain)

Does this address any currently open issues?

• 1402

Outside contributors checklist

• [ ] Review the guidelines for contributing to this repository
• [ ] Read and sign the CLA and add yourself to the authors list
• [ ] Make sure you are making a pull request against the develop branch (not main). Also you should start your branch off develop
• [ ] Add tests that prove your fix is effective or that your feature works
• [ ] Add necessary documentation (if appropriate)

Thank you for contributing to SLEAP!

:heart:

[codecov[bot]]

Codecov Report

Merging #1404 (1eae024) into develop (0e7a372) will increase coverage by 0.00%. The diff coverage is 83.33%.

@@           Coverage Diff            @@
##           develop    #1404   +/-   ##
========================================
  Coverage    72.73%   72.74%           
========================================
  Files          133      133           
  Lines        23719    23723    +4     
========================================
+ Hits         17252    17257    +5     
+ Misses        6467     6466    -1     

Impacted Files	Coverage Δ
sleap/gui/commands.py	60.91% <83.33%> (+0.16%)	:arrow_up:

:mega: We’re building smart automated test selection to slash your CI/CD build times. Learn more