ucode: parse ucode plugin scripts in raw mode, init search path

ucode: parse ucode plugin scripts in raw mode, init search path

It makes little sense to execute rpcd ucode plugin scripts in template
mode since those scripts are supposed to output structured JSON data,
so change the parse config to compile scripts in raw mode.

Also initialize the default library search path which is required in
recent ucode versions.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>