Add TCL_UTF_MAX log to status report

[michaelortmann]

Found by: michaelortmann Patch by: michaelortmann Fixes:

One-line summary: Add TCL_UTF_MAX log to status report

Additional description (if needed):

Test cases demonstrating functionality (if applicable):

.status
[...]
Tcl library: /usr/lib/tcl8.6
Tcl version: 8.6.14 (header version 8.6.14)
Tcl is threaded.
Tcl TCL_UTF_MAX: 3
[...]