Kibana verbose logging does not report http response message on errors

[elasticmachine]

Original comment by @ppf2:

With verbose logging in Kibana, reporting POST responses (Eg. from Watcher) does not provide any response message when it encounters an error:

respons [19:08:34.846] POST /api/reporting/generate/dashboard/New-Dashboard?_a=(filters%3A!()%2Coptions%3A(darkTheme%3A!f)%2Cpanels%3A!((col%3A1%2Cid%3ANew-Visualization%2CpanelIndex%3A1%2Crow%3A1%2Csize_x%3A3%2Csize_y%3A2%2Ctype%3Avisualization)%2C(col%3A4%2Cid%3A'New-Visualization-(Date)'%2CpanelIndex%3A2%2Crow%3A1%2Csize_x%3A9%2Csize_y%3A2%2Ctype%3Avisualization)%2C(col%3A1%2Ccolumns%3A!(_index%2C_id%2C_type%2Chost%2Cmessage%2C'%40version'%2Csequence%2C'%40timestamp'%2C_source)%2Cid%3ANew-Saved-Search%2CpanelIndex%3A3%2Crow%3A3%2Csize_x%3A12%2Csize_y%3A3%2Csort%3A!('%40timestamp'%2Cdesc)%2Ctype%3Asearch)%2C(col%3A1%2Cid%3ATest-Timelion-Panel%2CpanelIndex%3A4%2Crow%3A6%2Csize_x%3A3%2Csize_y%3A2%2Ctype%3Avisualization))%2Cquery%3A(query_string%3A(analyze_wildcard%3A!t%2Cquery%3A'*'))%2Ctitle%3A'New%20Dashboard'%2CuiState%3A())&_g=(refreshInterval%3A(display%3AOff%2Cpause%3A!f%2Cvalue%3A0)%2Ctime%3A(from%3Anow-5y%2Cmode%3Aquick%2Cto%3Anow))&sync= 400 16ms - 9.0B

In the above example, the POST returns a 400 status code, but the actual response message (which is the most important part) is discarded. We should include the error and message in addition to the statusCode from the response.

[tsullivan]

Closing via #28629