sdk: evict unchecked_div_by_const

[buffalojoec]

Problem

Working toward evicting RentCollector from the SDK, this is the lowest leaf node dependency that needs to be split out.

See #3932

Summary of Changes

Split unchecked_div_by_const into its own crate.

[kevinheavey]

I'm fine to pull this out but in #3855 I Just replace it with a constant and a static assertion:

// the !=0 check was previously done by the unchecked_div_by_const macro
#[cfg(test)]
static_assertions::const_assert!(DEFAULT_TICKS_PER_SECOND != 0);
const DEFAULT_SLEEP_MICROS: u64 = (1000 * 1000) / DEFAULT_TICKS_PER_SECOND;

Do we use the macro anywhere else?

[joncinque]

It doesn't look like it's used outside of poh-config, which was already extracted, so we'll probably be fine without this. @buffalojoec is the extracted solana-poh-config good enough for SVM?

[buffalojoec]

I'm fine to pull this out but in #3855 I Just replace it with a constant and a static assertion:

Oh nice, yeah that's fine with me. I'll close this one, and I can move up my stack.

is the extracted solana-poh-config good enough for SVM?

Yep, I just needed it to move toward RentCollector.