Server: add the "coverage depth" to "SequencesAroundLocation" if parameter "depth" exist

Signed-off-by: Jean-François Erdelyi <jean-francois.erdelyi.1@ulaval.ca>
All: the distribution graph is constructed by the server informations

Signed-off-by: Jean-François Erdelyi <jean-francois.erdelyi.1@ulaval.ca>