Align bucket and tranche expiry

[0xdewy]

Aligh bucket and tranche expiry to both use beginning or end of each of their cycles when calculating rewards shares.

[0xdewy]

in allocateStake() the variable currentBucket is re-calculated during getAllocatedCapacities & updateAllocatedCapacities & updateTranches. may be worth passing it as a parameter to those fn's when we are optimizing things.

ie. uint16 currentBucket = (block.timestamp / BUCKET_DURATION).toUint16();

[0xdewy]

Surge threshold still needs to get updated from 80 to 90 in a couple places

[0xdewy]

bucket expiry observes the beginning of the bucket, but the tranch expiry looks at the end. Anatol explained to me, that it works out the same, but it was just something that stood out to me while reading through it.

[roxdanila]

cc @shark0der - any actionables?

[shark0der]

the variable currentBucket is re-calculated

Technically this may only marginally improve the gas. The recalculation is using opcodes TIMESTAMP - 2 gas, BUCKET_DURATION is a constant ie one PUSH32 - 3 gas, DIV - 5 gas. Calculating and passing as a parameter will push it on the stack before the jump so we get at most something less than 10 gas improvement which means it's more important to take a look at the syntactic and code style rather than improve for gas here. A final round of gas improvements should be performed when everything is implemented and then we can touch on this then

Surge threshold still needs to get updated from 80 to 90 in a couple places

We will surely do a final pass through the code at the end, fixing outdated comments, no need to address it separately

Bucket expiry observes the beginning of the bucket, but the tranch expiry looks at the end

Technically just a semantic change, but I guess it would make sense to align these two. Since it's the only thing that we can triage, @kyledewy please change the title of the current issue and update the description to reflect the change needed.