Fixing unclear & nondescriptive errors

[itamarreif]

general

• [x] partial failure due to 0,0 true amounts in deposit (see issue 277)

wrapf

docs sdkerrors

• [x] clean out redundant or no longer used errors
• [x] get rid of redundant Wrapf errors
• [x] standardize Wrapf statements
  • [x] add standard Wrapf message for each error in types/errors.go
  • [x] replace all existing Wrapf with the same format

deposit

• [x] a 0,0 deposit currently triggers ErrInvalidType - change to specific error type
• [x] a deposit that is ratio'd down to 0,0 will return ErrAllDepositsFailed because it will continue after pool.Deposit
  • [x] partial failure should fail the tx
  • [x] get rid of passDeposit

withdraw

• [x] fix withdraw when tick doesn't exist returns ErrNotEnoughShares

swap

• [x] slippage errors from issue 225

cancel limit order

• [x] trancheUser fail returns same error as tranche fail
• [x] zero-amount error was not descriptive

withdraw filled limit order

• [x] trancheUser fail returns same error as tranche fail
• [x] fix withdraw when tick doesn't exist returns ErrNotEnoughShares
• [x] ErrCannotWithdrawLimitOrder is the same both for cancel and withdraw
  • for cancel - nothing left to cancel
  • for withdraw - nothing left to withdraw
  • they are for different side of the trade, so should give different errors