Ability to remove all tags from a layer or group
It is often useful to un-tag a layer, or a number of selected layers, en-masse.
This is helpful when layer naming triggers auto-tagging in error, or if multiple tags have been applied by the user in error.
A simple right-click->"Clear All Tags" in the Puppet Panel would do the trick.
If a single layer is selected, clear all tags from that layer.
If multiple layers are selected, all tags should be removed from all selected layers.
If a group is selected, all layers and groups contained in the group should have their tags cleared.
