#3577219: Add Multi-Value Image/Video Prop Support

Closes #3577219

Testing Instructions

• Enable 'canvas_test_sdc' module. Create a new Canvas page and place 'Canvas test SDC for image gallery (>1 image)' component.
• Add couple of media images by clicking 'Add media' button. This is the old design where drag handle does not exists.
• Now enable 'canvas_dev_mode', Create another Canvas Page and place the same component to verify the updated design.
• This issue is only related to design change and does not fixes any issue which exists in 1.x branch also before this branch is merged.
• Placement of Cardinality message is same as it was in old designs.

Another way of Testing (Including Video):

• Enable 'canvas_test_sdc' module.
• Enable 'canvas_test_article_fields' module and add an Article at '/node/add/article'
• Go to 'canvas/editor/node/1' and add Video/Image to verify the new designs in right Panel.