[449167] Fix regression caused by Removing A3 references in Sirius MM

Add a migration participant to update object values in VSM before
loading this objects from XML file.

By using this added migration, attributes that use the default value of
sizeComputationExpression of EdgeStyleDescription and
colorValueComputationExpression of InterpolatedColor in VSM ("1") were
replaced by the Acceleo expression ("[eContents()->size()/]").

Bug: 449167
Change-Id: Id1001924abc2b3942fc98d9e98463e9bd57a650d
Signed-off-by: Belqassim Djafer <belqassim.djafer@obeo.fr>