Note that since the markup might exist for other reasons, it has
to be turned on with a preference setting. (It goes through a set
of bitflags so the same architecture can be used for other markup
structures that we might want to support in the future.)
Note also that this is more about engineering nomenclature than
visual formatting. In that respect it's more similar to overbar
than italic or bold.
In particular, don't move block back to start when duplicating,
and don't move crosshair back to start when doing a cut, copy, or
paste.
Also fixes undo for libEdit block duplicate.
Fixes: lp:1740138
* https://bugs.launchpad.net/kicad/+bug/1740138
1) when duplicating don’t keep original hidden until end of drag
2) reset selectionArea when showing it so it doesn’t flash in its previous location
3) center a pasted block on the cursor
4) don’t draw the source selectionArea when pasting a block
5) implement selection-style highlighting for contents of blocks
6) add pasted items to view so they don’t disappear when the block is placed
Fixes: lp:1747197
* https://bugs.launchpad.net/kicad/+bug/1747197
Jonatan Liljedahl
Jeff Young
jean-pierre charras
Tomasz Włostowski
Maciej Suminski