feat: use expansion visibility service

[gbarkhatov]

• Centralize complex visibility logic for staking expansion delegations

Closes #1530

[Copilot]

Pull Request Overview

This PR introduces a new hook useExpansionVisibilityService to centralize complex visibility logic for staking expansion delegations. The hook determines which delegations should be visible in different UI parts (Activity tab vs Verified Expansion Modal).

• Centralizes delegation visibility logic into a dedicated service hook
• Implements filtering rules for Activity tab and Verified Expansion Modal
• Adds logic to detect broadcasted expansions and hide original transactions when appropriate

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