[Feature] Print number of variables when calling leo run

[vicsn]

🚀 Feature

It would be great if we would also print the number of internally generated variables:

• 'helloworld.aleo/main' - 33 constraints and X internal variables (called 1 time)

Motivation

Since introducing AleoNet/snarkVM#2444
Its useful for developers to know how many variables their program is generating.

This will also require adjusting the CallMetrics struct.

[asharma13524]

just made some changes to my snarkos version here locally and deployed to capture num of variables for now, but could possibly take this work up depending on best approach we want to take here @d0cd