[OGUI-1902] Add abort listener on query endpoint with signal to query service to drop DB connection if so

[graduta]

I have JIRA issue created

• branch and/or PR name(s) includes JIRA ID
• issue has "Fix version" assigned
• issue "Status" is set to "In review"
• PR labels are selected
• FLP integration tests were ran successful

PR which:

• adds listeners on the response (close, finish) events together with an abort controller so that the server can stop any ongoing queries if client cancells the request
• move towards using pool.connection instead of pool.query so that we can drop the connection in case of signal being aborted.
• add cancellation methods with AbortError classs
• attempt to improve stability of test on front-end