Adds accounts lt hash featurization

[brooksprumo]

Problem

The accounts lt hash must be enabled cluster-wide, so it requires a feature gate. There currently isn't one.

Summary of Changes

• Add the accounts lt hash feature
• Mix in the accounts lt hash into the bank
• Remove the Epoch Accounts Hash

Feature Gate Issue: #3333

[HaoranYi]

what's the plan for feature enable lt hash?
replace EAH?

[brooksprumo]

what's the plan for feature enable lt hash? replace EAH?

Yep! This feature gate does two things:

1. mixes the accounts lt hash into the bank hash
2. removes the EAH

[HaoranYi]

Can we add this #3334 (comment) to the feature code comments?

[brooksprumo]

Can we add this #3334 (comment) to the feature code comments?

Yes! Thank you, I forgot about that.
(And once there's a SIMD, I'll change it to that number)

[jeffwashington]

lgtm

[HaoranYi]

lgtm

Code at time of review is missing features

[brooksprumo]

I've dismissed the current reviews and moved this PR back to a draft. I need to implement calculating the accounts lt hash at feature activation time too, which was missing. After implementation and testing, I'll re-request reviews. Thanks for bearing with me here.

[HaoranYi]

I made a first pass review of this PR.
Overall, looks good.
I commented with a few questions.

[HaoranYi]

lgtm

[jeffwashington]

lgtm