[usecase-webapi] Improve WebSocket usecase

- Adjust the case with screen view

Impacted tests(approved): new 0, update 1, delete 0
Unit test platform: [Tizen IVI]
Unit test result summary: pass 1, fail 0, block 0
we should distinguish connection timeout and connection error. If timeout, remind use to check if the tinyweb server is enable, if connection error, show error log.