Lightweight log macro

[febo]

Problem

Currently, logging messages that require formatting are a bit heavy on the CU consumption. For example, a simple msg!("lamports={}", lamports) log can take ~627 CUs.

Solution

Create a lightweight log! macro that improves CU consumption.

• log! macro
• Log trait to define custom logic for formatting/logging
• pinocchio-log crate
• Optimize and measure CU

Below is a sample of the improvements observed when formatting log messages, measured in terms of compute units (CU):

Ouput message	log!	msg!	Improvement (%)
"Hello world!"	103	103	-
"lamports={}" + u64	374	627 (+253)	40%
"{}" + [&str; 2]	384	1648 (+1264)	76%
"{}" + [u64; 2]	601	1060 (+459)	44%
"lamports={}" + i64	389	660 (+271)	41%
"{}" + [u8; 32] (pubkey bytes)	3147	8401 (+5254)	62%