* Add and Scale to VaultCreate
* Add round-trip calculation to VaultDeposit VaultWithdraw and VaultClawback
* Implement Number::truncate() for VaultClawback
* Add rounding to DepositWithdraw
* Disallow zero shares withdraw or deposit with tecPRECISION_LOSS
* Return tecPATH_DRY on overflow when converting shares/assets
* Remove empty shares MPToken in clawback or withdraw (except for vault owner)
* Implicitly create shares MPToken for vault owner in VaultCreate
* Review feedback: defensive checks in shares/assets calculations
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Co-authored-by: Ed Hennis <ed@ripple.com>
