Cosmos-sdk: Rename "accum" in distribution

[cwgoes]

Validators already have an "accum" in the Tendermint proposer election algorithm, also giving them an unrelated "accum" in the SDK-side fee distribution logic invites confusion. I think we should rename the latter.

cc @rigelrozanski @alexanderbez

[alexanderbez]

Per @ebuchman we should rename both ideally 😄

[cwgoes]

Ref https://github.com/tendermint/tendermint/issues/2915

[ValarDragon]

How about renaming SDK accum to SharesOfFeeRewards or some similar variant? (I think of it as shares in my head at least)

[rigelrozanski]

This is definitely some kind of shares mechanism, but it also an accum mechanism (as these units accumulate) - I think that we should maintain "accum" in the title - but maybe prefix it: distrAccum

I'd also be okay with collections -> maybe this is the best, unique from staking shares, and tendermint accum, distribution collections :)

[alexanderbez]

accumRewardShares?

[ValarDragon]

I'm not the biggest fan of the name accum, but its probably not worth the bikeshed, I'm happy with rewardShares, sharesOfFeeReward, accumRewardShares, and distrAccum

(rewardShares / feeRewardShares are my favorite)

I'm kind of confused by collection, since collections are what you get after withdrawing, not the actual share itself. (I do like collectionShares though). also tendermint's accum has been renamed to proposer priority.

[rigelrozanski]

oh I like priority... I'm good with collectionShares

[rigelrozanski]

@cwgoes is this issue relevant in F1?

[cwgoes]

No; validators don't have an "accum" by any name.