Need to update for Harness UI MIgration

[kleinjoshuaa]

Split will be moving into the Harness UI - and some some API endpoints will be deprecated.

https://help.split.io/hc/en-us/articles/34773611130893-Before-and-After-Guide-API-for-Split-Admins

eg - api keys, projects, users, restrictions and groups.

This may need to have an option in the provider to denote if their account has been migrated or not - there isn't an api way to find this out unfortunately.

The good news is I think these should be able to be covered by the harness terraform provider (since these will now be harness keys, harness groups, harness projects, etc) so unless you want to I don't think you'd need to re-implement these from scratch.

The simplest solution may be just to enable support for x-api-key auth and then deprecating the resources that use the deprecated endpoints when using the x-api-key (essentially a 'harness mode' for the terraform provider)

[dtk-DaveKarow]

@davidji99, I'd happily get you early access to a migrated split org on app.harness.io, along with access to technical resources for Q&A as needed.

[kleinjoshuaa]

#211 Did a first go at an attempt for these changes

[davidji99]

Let me take a look at #211. A migrated and not migrated org would be helpful to sanity check.

[dtk-DaveKarow]

@davidji99 @kleinjoshuaa gave me a heads up in July that you wanted migrated and non-migrated orgs to test with, but somehow I didn't see that in Slack at the time. Just saw it for the first time a minute ago. I'll get working on that for you TODAY.
(I suspect this was a while on vacation thing that I missed when I came back... apologies!)