base-files: profile: allow profile.d to set EDITOR

base-files: profile: allow profile.d to set EDITOR

With a profile.d configuration in place that sets the EDITOR variable,
the automatic terminal 'resize' logic would not trigger. Which then
would possibly lead to a 80x24 fallback on the debug serial console.

This can simply be avoided by setting a flag variable when the shell
is first opened, then processing all profile.d includes, trigger the
'resize' depending on the flag and shell-level and finally only set
EDITOR to some default if it is still unset.

Signed-off-by: Johannes Schneider <johannes.schneider@leica-geosystems.com>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>