If someone has the log viewer page opened, log all messages and show them. Even if no log writer or only screen is configured

[tsteur]

From matomo-org/matomo#7239 (comment)

This is probably not achievable easily, but it would be great if we could change the log level just for the LogViewer page. Ie, selecting DEBUG in the LogViewer would display DEBUG logs, but they wouldn't get written to the database or file (so they would have to be written to a temporary location and then removed later).