Update "delegate" functionality to work on Base

[bagelface]

Description 🗒️

Update webapp delegate functionality to work with Base contracts.

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Details 🏗️

• Update delegate function: Update the webapp delegate functionality to work with the Base contracts. All functionality available on the mainnet proposal creator should be available on the Base proposal creator.

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Acceptance Criteria ☑️

1. All of the changes described in the "Details" section above are implemented and tested.
2. Code is clear, clean, and properly documented.
3. UI changes are sensible and non-regressive.