ENH: Expose qMRMLTreeView scene model and proxy model to python.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23228 3bd1e089-480b-0410-8dfb-8563597acbee
STYLE: Remove forgotten debug statement in installExtension

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23229 3bd1e089-480b-0410-8dfb-8563597acbee
ENH: Exclude json extension from git hook line lengths check

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23230 3bd1e089-480b-0410-8dfb-8563597acbee
BUG: Fix failing qSlicerExtensionsManagerModelTest

Commit r23200 added icon URL to extension metadata and commit 9dc157 [1]
updated the server to return the iconurl, this commit
fixes the server mock data also adding iconurl .

[1] https://github.com/midasplatform/slicerpackages/commit/9dc1575d2bf9d3c053700f541cdb5034f8328eee

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23231 3bd1e089-480b-0410-8dfb-8563597acbee