SIP-2: External transaction bundles support

[philipsu522]

Discussion for https://github.com/sei-protocol/sips/blob/main/sips/sip-2.md

[MariaEverstake]

Hey everyone! Everstake fully supports this proposal. Implementing an MEV-aware transaction flow will not only improve fairness across the network but also unlock new opportunities for economic efficiency, benefiting both validators and the wider Sei ecosystem.

We're excited to see Sei embrace these advancements and look forward to contributing to their successful rollout.