feat(CHAIN-1796): add CBMulticall contract

[jackchuma]

Adds the Multicall contract utilized by our eth recovery task. In the regular Multicall3 contract, the aggregate3Value function has the following line:

require(msg.value == valAccumulator, "Multicall3: value mismatch");

This did not allow us to delegatecall from a multisig because you cannot send a value with this call type. Since our multisig already holds ETH, removing the above require statement allows calling aggregate3Value via delegatecall.

[linear]

CHAIN-1796 Add CBMulticall to `contracts` repo

[cb-heimdall]

✅ Heimdall Review Status

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[leopoldjoy]

Looks great!

[cb-heimdall]

Review Error for leopoldjoy @ 2025-08-11 19:19:18 UTC
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