projects for grid node's list : add assigned operator + leaflet maps use filters

[beaudu]

Two enhancements for project display/filter in grid node's list display (showGRID.pl):

• use the remote operator to assign operator(s) to a project:

  • change the field name in form,
  • display name(s) in a separate column for project=on,
  • display a new icon for project=off.

• allow multiple projects.

[beaudu]

assigned operators for node's project is done by commit 2c1d4e0.