Bugfix: ensure pan/zoom buttons work, along with spacebar keybinding

[psobolewskiPhD]

Description

This fixes issues with Pan/Zoom buttons (layer controls) not working and the spacebar keybinding to activate pan/zoom mode also not working.
In #4894 there was some refactoring which introduced the bugs, see my investigation here: #5654

This PR fixes the typo, lack of proper layer types, and now moves the hold_for_pan_zoom to be a Viewer keybinding. As a result, this keybinding isn't hard-coded anymore, but is now settable in the Preferences > Shortcuts.

Type of change

• Bug-fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

References

closes #5654

How has this been tested?

Good question! All tests were passing before this PR, despite the fact that things were broken. So I'm open to suggestions how to improve tests so we catch stuff better.

Final checklist:

• My PR is the minimum possible work for the desired functionality
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• If I included new strings, I have used trans. to make them localizable.
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[codecov]

Codecov Report

Merging #5669 (6eaea7c) into main (8a793b9) will increase coverage by 0.00%.
The diff coverage is 94.11%.

@@           Coverage Diff           @@
##             main    #5669   +/-   ##
=======================================
  Coverage   89.85%   89.86%           
=======================================
  Files         611      609    -2     
  Lines       51669    51673    +4     
=======================================
+ Hits        46428    46434    +6     
+ Misses       5241     5239    -2     

Impacted Files	Coverage Δ
napari/_qt/layer_controls/qt_shapes_controls.py	88.88% <ø> (ø)
napari/utils/shortcuts.py	100.00% <ø> (ø)
napari/components/_viewer_key_bindings.py	97.33% <81.81%> (-2.67%)	⬇️
...apari/components/_tests/test_viewer_keybindings.py	100.00% <100.00%> (ø)
napari/layers/image/_image_key_bindings.py	78.04% <100.00%> (ø)
napari/layers/points/_points_key_bindings.py	100.00% <100.00%> (ø)
napari/layers/shapes/_shapes_key_bindings.py	98.86% <100.00%> (ø)
napari/layers/surface/_surface_key_bindings.py	93.33% <100.00%> (ø)
napari/layers/tracks/_tracks_key_bindings.py	93.33% <100.00%> (ø)
napari/layers/vectors/_vectors_key_bindings.py	93.33% <100.00%> (ø)

... and 3 files with indirect coverage changes

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[Czaki]

Could we move pan/zoom from layers to viewer with action like:

def pan_zoom(layerlist: LayerLis):
    selection = layerlist.selection
	if len(selection) != 1:
       yield
       return
    prev = selection[0].mode 
    try:
        selection[0].mode = PanZoom
    finally:
        selection[0].mode = prev

This is dummy code written form memory and may not work.

Such action will allow having one global shortcut for all layers.

[psobolewskiPhD]

Ok, I moved it over to napari/components/_viewer_key_bindings.py
and moved/adjusted the tests.
It's now editable in the Viewer shortcuts.
Personally, I still don't think this should be editable, but just a napari thing, but I get that I'm coming from a different PoV, so sure, why not.

[brisvag]

I like it! Configurability doesn't really hurt here I think :)

[Czaki]

Until we do not have a mechanism to prevent overwrite in setting built-in shortcuts, then making it configurable is better.