Add 'tiles' property to circles with a copy of tiles needed to draw the shape
Add 'sequenceName' property to circle shapes

This is the name of the property for the sequence of tiles
in the namespace "projetmedea.fr".
Add tilesCount property to shape circles
Compute top/left position of tiles in each shape

This completes step J of the algorithm:

  J) to plot each circular shape, compute the center position (even
     circles) or center tile (odd circles) and shift the precomputed
     position of each tile accordingly; for lines, position the first
     tile at the top left of the line then shift the position of each
     following tile by 1 from the top (vertical lines) or the left
     (horizontal lines).

I am keeping intermediate properties for now, until I can confirm
visually that the position computed for the tiles is correct.