Initial pcu support implementation

[toptobes]

WIP!!!!

Did my best to follow the conventions of the current code, down to the grammar

Adds three new clients:

• PcuGroupsClient
  • This serves a similar role to AstraDBOpsClient in that it doesn't work with one specific PCU group, but rather lets you create and find them
• PcuGroupOpsClient
  • This serves a similar role to DbOpsClient in that it lets you manage a specific group (RUD),
• PcuGroupDbAssociationsClient
  • This is the black sheep of the family and manages associations between PCU groups and datacenters
    • I'm not very set on the naming of its methods
    • It's coded defensively, in anticipation of potentially other PcuGroup*AssociationsClients
      • Streaming, for example, may have PCU support in the future. It's not very clear to me though.

Three new exceptions too:

• PcuGroupDbAssociationNotFound
• PcuGroupNotFoundException
• PcuGroupsNotFoundException

As well as a bunch of new domain classes.

Example usage:

val pcuGroupsClient = new AstraOpsClient(<token>).pcuGroups()

val pcuGroupEntity = pcuGroupsClient.create(
    PcuGroupCreationRequest.builder()
        .title("pcu_group_32.5")
        .cloudProvider(AWS)
        .cloudRegion("mars-cloud-station-3")
        .minCapacity(1)
        .maxCapacity(3)
        .build()
);

val pcuGroupDao = pcuGroupsCilent.group(pcuGroupEntity.getUuid());

pcuGroupDao.datacenterAssociations().associate(<datacenterId>);

while (!pcuGroupDao.isActive()) {
    Thread.sleep(500);
}

if (pcuGroupDao.datacenterAssociations().exist(<datacenterId>)) {
    System.out.println('yay');
} else {
    cry();
}

Todo:

• More client-side validations
  • Partially because the server is not great at validating its own requests
• Some client-side defaults in creations
  • Things that should be defaulted on the server but aren't reliably done so
• Play with changing PcuGroupDbAssociationsClient around
  • It just has that je ne sais quoi which irks me
• Potentially rename some things on the client side for consistency/clarity
  • Mainly things like uuid -> id or min -> min_capacity
• Potentially add 'wait for status' operations

Things can and will change as I get more answers to my questions from the PCU team.