Add a button to enable WFS capabilities directly

[Antoviscomi]

When a user goes to config his project but one of the layers in, is not flagged in wfs capabilities, it receive the warning,
then he must close the Lizmap plugin and go to the Project Properties to select the capabilities for this layer.
It would be much quicker to have a button that opens the properties panel, directly from Lizmap plugin, to allow the user to flag the layer more quickly