New Raido schema: LegacyMetadataSchemaV1

[ardc-shorn]

Raido now supports an explicit concept of a "legacy" schema.
Migrated legacy raid data (and new raids minted via the deprecated V1 endpoint) use the legacy schema.

When a legacy schema raid is accessed via the public read endpoint, Raido does the "cross-walk" to publish it as a PublicRaidMetadataSchemaV1.
When contributor and organisation are added as mandatory fields, the legacy schema will not change.
The cross-walk will add "placeholder" values in all mandatory fields where the legacy data does not conform to the raid standard.

Before a legacy raid can be edited - it must be "upgraded" from the legacy schema to the raidoV1 schema. During this process, the user will be prompted to provide all data that is needed for a legacy raid to become a raido V1 (i.e. contributor, organisation, etc.)
I have not yet implemented the upgrade screen (user is told they have to upgrade before they can edit, but then they're stuck).

Any client using the non-public API has to be implemented to deal with the possibility that it may be returned a LegacyMetadataSchemaV1 or a RaidoMetadataSchemaV1.

The concept of "Raid" vs "Raido" metadata schema is discussed here: https://github.com/au-research/raido-v2/blob/main/api-svc/idl-raid-v2/src/readme.md

Legacy schema functionality has been deployed to demo environment.