Allow mutliple versions of the same instance

[sebg-mio42]

Currently it is not possible to have multiple versions of them same instance. However, it would be a useful feature to have when creating examples and having data for multiple points in time.

A simple example would be:

patient-dfe48ee5-88dc-4784-aed6-ac5a6d95c253-v1.fsh

Instance: dfe48ee5-88dc-4784-aed6-ac5a6d95c253
InstanceOf: Patient
Description: "An example of a patient with a license to krill."
* meta
  * versionId = "1"
  * lastUpdated = "2024-06-17T01:01:01.000+00:00"
* name
  * given[0] = "James"
  * family = "Pond"

patient-dfe48ee5-88dc-4784-aed6-ac5a6d95c253-v2.fsh

Instance: dfe48ee5-88dc-4784-aed6-ac5a6d95c253
InstanceOf: Patient
Description: "An example of a patient with a license to kill."
* meta
  * versionId = "2"
  * lastUpdated = "2024-06-18T01:01:01.000+00:00"
* name
  * given[0] = "James"
  * family = "Bond"