[Console] Improve handling of invalid requests

[yuliacech]

Currently, when a request is invalid, the parser only contains information about the start of the request and the logic in requests_utils.ts (see this line) computes the line number where the invalid request should end. When there are comments following an invalid request, they are highlighted together with the request because the end line is detected incorrectly.

Screenshot

[elasticmachine]

Pinging @elastic/kibana-management (Team:Kibana Management)