PIM-3196 Improve the view element registry
PIM-3196 Rename ViewTabExtension to ViewElementExtension and refactor view element rendering
PIM-3196 Replace BaseTab with BaseViewElement
PIM-3196 Refactor visibility checkers
PIM-3196 Update view element configuration
PIM-3196 Update the templates
PIM-3196 Pass context to ViewElementInterface::getParameters()
PIM-3196 Address comments
Merge pull request #1781 from akeneo/PIM-3196-extra

PIM-3196 Refactor the view element feature