MEDIUM: stats: expose the same flags for CLI and HTTP accesses

MEDIUM: stats: expose the same flags for CLI and HTTP accesses

The HTML dump over HTTP request may have several flags including
ST_SHLGNDS (to show legends), ST_SHNODE (to show node name),
ST_SHDESC (to show some descriptions).

There's no such thing over the CLI so we need to have an equivalent.
Let's compute the flags earlier so that we can make use of these flags
regardless of the call point.