[Supplier] Implement an "Upstake" Command

[Olshansk]

Objective

Add CLI support for partially updating stake parameters without requiring full re-specification.

Origin Document

btw @olshansky stake command or even "restake" command is needed, to update stake partially, like "increase amount" without need to specify everything, or update "services" without specify everything

Goals

• Improve operator experience by reducing friction in common stake update operations.
• Enable partial stake updates (e.g. amount or services) through pocketd.

Deliverables

• Add pocketd tx supplier update-supplier --stake command to increase stake without re-specifying services or chains.
• Add pocketd tx supplier update-supplier --services command to update service params without re-specifying stake amount or chains.
• Add validation logic to ensure partial updates do not invalidate the current stake state.
• Evaluate if this should be part of pocketd tx supplier stake-supplier or if it should be in a new pocketd tx supplier update-supplier command`

Non-goals / Non-deliverables

• No changes to protocol-level staking logic.
• No changes to unstake or claim behavior.

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Creator: @olshansky
Co-owners: @bryanchriswhite @jorgecuesta

[jorgecuesta]

@Olshansk just be careful about how the "rev_share" are parsed/managed here also in relation to this: #1371