Minimum unit of data should be 64KB

Since 0chain advocates minimum unit of data to be 64KB per file we need to correct price calculation for data stored in an allocation.
If `S` is size of data in writemarker and `W` is the write price then price calculation in storage smart contract should be:

`Price(p) = Ceil_of(S / 64KB) * 64KB * W`

However client can be clever to upload multiple files say, 1KB each and commit them with single writemarker. In this case if client had uploaded 64 such files then total size in writemarker is 64KB in which case above price calculation is not enough. Blobber however can decide whether to accept such writemarkers or not. In the above case, blobber should expect to get total size in writemarker to be 64 *64KB and if not then it should reject the writemarker.

This issue is an alias of https://github.com/0chain/gosdk/issues/451

The issue relates to price calculation in the storage smart contract for data allocations. Look at the writemarker handling and price calculation logic, likely in the smart contract code. Understand how blobbers validate writemarkers. The change involves adjusting the formula to use a 64KB minimum unit and possibly adding blobber-side validation. Check linked issue gosdk#451 for context.

Rédigé par le modèle d'indexation à partir du texte de l'issue.