feat(web): add search functionality and empty states to MCP market

- Add search input with debouncing (500ms) to filter MCP services by keywords
- Implement server-side search via keywords parameter in getMarketMCPs API call
- Add new i18n strings for empty states: marketNoData, marketNoDataDesc, marketNoSearchResult, marketNoSearchResultDesc
- Replace client-side filtering with server-side search for better performance
- Update Empty component display to show different messages for no data vs no search results
- Remove BodyWrapper component and implement custom empty state handling
- Add searchTimerRef to manage debounce timer lifecycle
- Update loadMore callback to include searchKeyword parameter for pagination consistency
- Add allowClear prop to search input for better UX
- Remove conditional rendering of search input to keep it always visible

web/src/i18n/en.ts

@@ -1820,6 +1820,10 @@ Memory Bear: After the rebellion, regional warlordism intensified for several re
       marketRefresh: 'Refresh',
       marketConfigBtn: 'Configure',
       marketConfigConnection: 'Configure Connection',
+      marketNoData: 'No Data',
+      marketNoDataDesc: 'This market currently has no available services',
+      marketNoSearchResult: 'No Search Results',
+      marketNoSearchResultDesc: 'No matching services found, please try other keywords',
       marketNoServices: 'No MCP Services Available',
       marketNotConnected: 'Not Connected to This Market',
       marketNoServicesDesc: 'This market currently has no available services',