Change FHIR server links to profiles in 1.2.x to point to the correct minor version

[jonnyry]

Most links to the FHIR server in the specification are pointing to the latest version of the profile.

Where structured profiles have been updated in 1.3, links in the 1.2.x spec should be updated to point to the correct minor version.

E.g. The following page has a link to the latest minor version of GPConnect-GetStructuredRecord-Operation:

https://nhsconnect.github.io/gpconnect/accessrecord_structured_development_retrieve_patient_record.html

This is incorrect for 1.2.x and should be updated to:

https://fhir.nhs.uk/STU3/OperationDefinition/GPConnect-GetStructuredRecord-Operation-1/_history/1.8

The same change should be applied for any of the other profiles.