feat: Add filtering and sorting for DAO members (#106)

[Karry2019web]

Description

Adds filtering and sorting functionality for DAO Members on the /dao page, as requested in issue #106.

Changes

• Search/Filter: Added a text input to filter members by account name
• Sort: Added a sort dropdown with options: Name, Votes, Power, EFX Staked, and Join Date
• Sort Direction: Toggle button for ascending/descending sort
• EFX Staked display: Shows EFX staked amount for each member when available
• Empty state: Shows "No members match your search" when filter yields no results

Implementation

• Added memberSearch, sortField, and sortDir data properties
• Added sortedMembers computed property with reactive filtering and sorting
• Client-side sorting/filtering on already-loaded members (works together with "Load More")
• Added Bulma has-addons field group for compact filter/sort controls