Expose T-Shirt Size On HostedClusters

User Story:

As the HyperShift scheduler, I want to be able to:

• see the size of each HostedCluster as translated to "t-shirt" sizes

so that I can achieve

• correct scheduling outcomes and warm-node reserve

As the HyperShift administrator, I want to be able to:

• configure how the size of each HostedCluster is translated to "t-shirt" sizes
• configure how often the size of each HostedCluster is translated to "t-shirt" sizes, both as the size gets larger and as it gets smaller

so that I can achieve

• tuning for auto-scaling of my management cluster

Acceptance Criteria:

Description of criteria:

• allow configuration for sizing buckets and sizing change throughput
• document the configuration above
• expose t-shirt sizes of hosted clusters

Engineering Details:

• design: https://docs.google.com/document/d/1VV1NZgrimSNFjJEH3PeZmUquey_YX3lm2l0FDwP8WDc/edit

This requires a design proposal.
This does not require a feature gate.