refactor: make AddressUtils an extension trait of Address

[cats2101]

Closes #791

Refactors AddressUtils from a unit struct with associated functions into an extension trait implemented on Address. This enables a more idiomatic calling pattern:

// Before
AddressUtils::function_delegate_call(context, target, data)?;
AddressUtils::verify_call_result_from_target(target, result)?;

// After
target.function_delegate_call(context, data)?;
target.verify_call_result_from_target(result)?;

All call sites in erc1967::utils, uups_upgradeable, and examples are updated. The private revert helper becomes a module-level function since it doesn't operate on an address.

All existing unit tests pass.

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[0xNeshi]

Hello @cats2101 , thank you for your contribution!
We're currently working on some higher priority tasks, we'll review the PR once those are handled.