Context menu on mural/space shows space list

No widget can be locked, spaces are auto-locked
Double tap on space creates a widget
Removed sidebar buttons
Can drag a space when holding the click for a short while
Added Timeline element
If holding alt while dragging ,the widgets are duplicated
Fixed hold to drag space broke after auto pan change
Added auto clustering when duplicating widgets with drag
Widgets are always dragged as ghosts

Whenever alt is toggled during drag, the ghosts rearrange
Fixed conflict between new ghost effect and dragging of spaces
Misc
Spaces have editable labels
Position
Fixed drag glitch
Move clustering to its own module

Added clustering to the context menu
Small improvement
Fixed spaces labels not collaborated
Implemented widget magnifier