Update elastic-agent-libs and update code to accommodate for the
breaking changes.

Fix the log level for event data on all outputs. Now the log level
from the message containing the evnt matches the one that does not
contain it.

Use the event logger instead of "trace level" for debug logs
containing events, both under Elastic-Agent and standalone Beat.

Fix the flaky python test. Moving the file instead of truncating it seems to solve the problem. Maybe the write was not properly synced to disk.

The advantage of moving the file is that if the test runs we can later inspect it.

Ensure the event data is not present in the normal log file

This commit extents the integration tests framework to read the events
log file.