improve FEC bench (!96)

we want to compare
- _naive recoding_: k-decoding followed by 1-encoding
- _komodo recoding_: k-recoding with $k = \#\text{shards}$

# results
> 💡 **Note**  
> we see that the _naive recoding_ is around 100 times slower compared to the _komodo recoding_ 🎉 

> 💡 **Note**  
> the format of the labels is always `{curve} / {k}`

![e2e](/uploads/9ffbae9188434f27f7018155de74982b/e2e.png)
![recoding](/uploads/17ddb76efe7719970849eeda655a68da/recoding.png)