Return full colormap dict in get_state (#5782)

# Description
When working with custom colormaps, reader and writers trying to use
that colormap will fail because the only information returned by
`Layer.get_state` is the colormap name. This works fine with builtin
colormaps, but anything custom will fail due to `[unnamed colormap 0]`
not existing.

By returning the full colormap model (in dict form) we can also account
for this.

Plugin writers and readers using `colormap` will likely break (like our
napari-svg) because they assume it to be a string.

Note that this includes #5805. which is a lot smaller and just a bug
fix.

# References
<!-- What resources, documentation, and guides were used in the creation
of this PR? -->

## Type of change
<!-- Please delete options that are not relevant. -->
- [x] Bug-fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [x] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] This change requires a documentation update

---------

Co-authored-by: Kyle I S Harrington <kephale@users.noreply.github.com>

napari/layers/image/image.py

@@ -952,7 +952,7 @@ def _get_state(self):
             {
                 'rgb': self.rgb,
                 'multiscale': self.multiscale,
-                'colormap': self.colormap.name,
+                'colormap': self.colormap.dict(),
                 'contrast_limits': self.contrast_limits,
                 'interpolation2d': self.interpolation2d,
                 'interpolation3d': self.interpolation3d,

napari/layers/points/points.py

@@ -1283,13 +1283,13 @@ def _get_state(self):
                 if self.data.size
                 else [self.current_face_color],
                 'face_color_cycle': self.face_color_cycle,
-                'face_colormap': self.face_colormap.name,
+                'face_colormap': self.face_colormap.dict(),
                 'face_contrast_limits': self.face_contrast_limits,
                 'edge_color': self.edge_color
                 if self.data.size
                 else [self.current_edge_color],
                 'edge_color_cycle': self.edge_color_cycle,
-                'edge_colormap': self.edge_colormap.name,
+                'edge_colormap': self.edge_colormap.dict(),
                 'edge_contrast_limits': self.edge_contrast_limits,
                 'properties': self.properties,
                 'property_choices': self.property_choices,

napari/layers/shapes/shapes.py

@@ -1524,11 +1524,11 @@ def _get_state(self):
                 'edge_width': self.edge_width,
                 'face_color': face_color,
                 'face_color_cycle': self.face_color_cycle,
-                'face_colormap': self.face_colormap.name,
+                'face_colormap': self.face_colormap.dict(),
                 'face_contrast_limits': self.face_contrast_limits,
                 'edge_color': edge_color,
                 'edge_color_cycle': self.edge_color_cycle,
-                'edge_colormap': self.edge_colormap.name,
+                'edge_colormap': self.edge_colormap.dict(),
                 'edge_contrast_limits': self.edge_contrast_limits,
                 'data': self.data,
                 'features': self.features,

napari/layers/surface/surface.py

@@ -514,7 +514,7 @@ def _get_state(self):
         state = self._get_base_state()
         state.update(
             {
-                'colormap': self.colormap.name,
+                'colormap': self.colormap.dict(),
                 'contrast_limits': self.contrast_limits,
                 'gamma': self.gamma,
                 'shading': self.shading,

napari/layers/vectors/vectors.py

@@ -397,7 +397,7 @@ def _get_state(self):
                 if self.data.size
                 else [self._edge.current_color],
                 'edge_color_cycle': self.edge_color_cycle,
-                'edge_colormap': self.edge_colormap.name,
+                'edge_colormap': self.edge_colormap.dict(),
                 'edge_contrast_limits': self.edge_contrast_limits,
                 'data': self.data,
                 'properties': self.properties,

setup.cfg

@@ -54,7 +54,7 @@ install_requires =
     magicgui>=0.3.6
     napari-console>=0.0.6
     napari-plugin-engine>=0.1.9
-    napari-svg>=0.1.7
+    napari-svg>=0.1.8
     npe2>=0.5.2
     numpy>=1.21,<2
     numpydoc>=0.9.2