qemu and Unicode characters on serial console

[Francois]

Hi qemu! I am wondering if it is possible to get Unicode support
through a stdio, or pty, serial console.
I am running qemu from CentOS stream
qemu-kvm-core-4.2.0-35.module_el8.4.0+547+a85d02ba.x86_64
My terminal and locale use UTF-8.
I am booting into the OVMF boot menu below, that lets me change the
language to French, however characters like é è ç are badly rendered.
I would expect the UEFI shell "edit" command to support unicode
characters but I cannot test this either.
My goal is to use Unicode characters in the boot entries (or "options
de bottes" as it is funnily translated today) so they look nice.

```
/usr/libexec/qemu-kvm \
-m 512M \
-net none \
-machine q35 \
-pflash ./OVMF_CODE.secboot.fd \
-pflash ./OVMF_VARS.fd \
-serial stdio \
-debugcon file:debug.log -global isa-debugcon.iobase=0x402
```

Cheers