LIMS-1108: Improve message re international shipping

[ndg63276]

JIRA ticket: LIMS-1108

Summary:

Improve the message displayed regarding international shipping

Changes:

• Add a new variable for a link to help with international shipping $facility_courier_countries_link
• If that variable exists, display the message at the top of the add shipment page, with the link
• Change the message displayed at the top of a shipment page depending on whether the dewar's country is supported for Synchweb-based shipping (ie UK), semi-supported (ie EU), or not supported.

To test:

• Click to add a new shipment, check no red message is displayed at the top
• Add $facility_courier_countries_link = 'https://www.diamond.ac.uk/Instruments/Mx/I03/I03-Manual/Shipping-Samples.html'; to config.php, refresh and check a red message appears at the top with a link
• View a booked shipment from the UK, check it shows a message about printing the air waybill
• View an unbooked shipment from the UK, check it shows a message about booking the air waybill
• View a shipment from the EU, check it shows a message including a link to help for EU users
• View a shipment from outside the EU, check it shows a shorter message without the EU link

[NKatti2011]

Looks good to me but conflicts need to be resolved