[v10] Delegate set claim type support

[basfroman]

Validator Claim Type Delegation

This PR implements validator claim type delegation, allowing validators to set their claim behavior (Swap/Keep) per subnet. Stakers with Delegated claim type will inherit the validator's claim type when claiming root emissions.

New Methods

• subtensor.get_validator_claim_type(hotkey_ss58, netuid) - Get validator's claim type for a subnet
• subtensor.set_validator_claim_type(wallet, hotkey_ss58, netuid, new_claim_type) - Set validator's claim type
• set_validator_claim_type_extrinsic - Low-level extrinsic calls (sync/async)

NOTE: Validator can't set Delegated claim type

Think of this logic like this:

• The validator is the chef who chooses the menu (Swap/Keep) for their restaurant (subnet)
• The staker with Delegated is the guest who says "I'll have whatever the chef recommends"
• The staker with Swap/Keep is the guest who orders a specific dish regardless of chef's recommendation
• If the chef says "as the guest decides" and the guest says "as the chef decides", the decision is undecided. (This is why the validator can't set Delegated.)

Example

• Validator Alice sets Keep on subnet 2
• Staker Charlie has Delegated claim type (default)
• When Charlie claims root emissions, they inherit Alice's Keep behavior → alpha stays on subnet 2, not swapped to TAO

Testing

• All tests pass successfully on a locally compiled node.

Subtensor base PR: opentensor/subtensor#2224