LIMS-1113: Shipping service dispatch redirect

[MattPrit]

JIRA ticket: LIMS-1113

Summary:
Adds the option to redirect to the shipping service to book shipments when requesting dispatch of appropriate Dewars.

Changes:

• Adds feature flag $use_shipping_service_redirect which enables/disables this feature
• On requesting Dewar dispatch, create a shipment request in the shipping service and redirect to the appropriate shipment workflow to book a shipment
• Use minimised dispatch request email for shipments booked via the new pathway

To test:

• Check that the appropriate dispatch form is displayed for academic, industrial, international users
• Check that the appropriate shipment request is created in the shipping service when requesting dispatch of a domestic academic Dewar
• Check that the minified dispatch-lite email template is used for such dispatch requests; ensure this has an appropriate link to where a Goods Handling operative can view and print the air waybill
• Check that the dispatch button links to the shipping service once a dispatch shipment request has been successfully created.

[MattPrit]

NOTE: Requires the addition of the externalShippingIdFromSynchrotron column to the Dewar table in ISPyB. Since _get_dewars in Shipment.php requires this column, the shipments table page, the shipment page, and possibly others will not work without this new column.

[MattPrit]

NOTE: Requires the addition of the externalShippingIdFromSynchrotron column to the Dewar table in ISPyB. Since _get_dewars in Shipment.php requires this column, the shipments table page, the shipment page, and possibly others will not work without this new column.

This change has now been made, see DiamondLightSource/ispyb-database#228