Calculation for estimated storage is incorrect

[mtlynch]

Sia-UI estimates the storage capacity based on the allowance:

The calculation is here:

Sia-UI/plugins/Files/js/sagas/files.js

Lines 50 to 52 in e6be3f6

	const estimate = new BigNumber(SiaAPI.siacoinsToHastings(action.funds)).dividedBy(response.storageterabytemonth).times(1e12)
	yield put(actions.setStorageEstimate('~' + readableFilesize(estimate.toPrecision(1))))

This calculation is essentially:

[allowance] / [storage_per_tb_per_month]

This is incorrect as it neglects upload cost and contract fees. It also misuses the storage price as the price per TB per contract period when it is actually the price per TB per month. The actual calculation requires Sia-UI to solve for tb_count in this equation:

allowance = (storage_per_tb_per_month * tb_count * months_per_contract) +
  (upload_per_tb * tb_count) +
  (contract_fees)

[DavidVorick]

don't know how this slipped through for so many months, this is an easy fix. @eddiewang

[eddiewang]

Thanks for the equation @mtlynch - i went ahead and implemented that into PR #800. Feel free to give it a glance to see if it makes sense. From my testing, the numbers look right.