Fix: Vault claimTime improvement

[Art3miX]

Opening an issue so we won't forget #276 .

Specifically answering this comment: #276 (comment)

what if the update doesn't happen for a while?

The strategist need the update to both get the most up to date withdraw fee, but also to have a "final count" of the amount to withdraw, strategist will not be able to start a withdraw from the position before completing an update.

So I think moving the claimTime parameter from individual request to a update makes sense logically.