JSON Error log to STDERR/STDOUT as an option

In the world of container orchestration, we have a common scenario in which we must collect and forward all log data produced by MariaDB, that isn't already forwarded to a file descriptor (slow query log, audit log, sql error log, etc).

It is not always possible, practical or secure for a log tailing process to mount the same data volumes that a VM or container is using.

Ideally we would want all the log data to be piped out to STDOUT or STDERR so we can capture all the data from a running container process.

If the log data was formatted, using JSON for example, we could easily separate out the different log types using a key, for example "log"="slow".