Emit missing events on important configuration changes

[k1rill-fedoseev]

Many state-changing operations do not emit events. Consider emitting events for important state
changes.
These operations include:
ZkBobPool:

• initialize()
• setTokenSeller()
• setOperatorManager()

ZkBobAccounting:

• _setLimits()
• _resetDailyLimits()
• _setUsersTier()

BobVault:

• setYieldAdmin()
• setInvestAdmin()

MutableOperatorManager:

• _setOperator()

ERC20Recovery:

• setRecoveryAdmin()
• setRecoveredFundsReceiver()
• setRecoveryLimitPercent()
• setRecoveryRequestTimelockPeriod()

Claimable:

• setClaimingAdmin()

Comments to changes:
Event describing the corresponding changes were added to:

• ZkBobPool: setTokenSeller(), setOperatorManager(), withdrawFee()
• ZkBobAccounting: _setLimits()
• MutableOperatorManager: _setOperator()

. For other parameters, they are not expected to be changed regularly and there is no any interest in their retrospective observations, thus such events considered as redundant:

• ZkBobPool: initialize() – an event will be emitted as part of _setLimits execution
• ZkBobAccounting: _resetDailyLimits() is not expected to be called regularly; _setUsersTier() already contains the event UpdateTier
• BobVault: setYieldAdmin() and setInvestAdmin() are not expected to be called regularly
• ERC20Recovery: setRecoveryAdmin()is not expected to be called regularly;setRecoveredFundsReceiver(), setRecoveryLimitPercent(), setRecoveryRequestTimelockPeriod()` do not require their retrospective observations whereas the current value can be extracted with getters.
• Claimable: setClaimingAdmin() is not expected to be called regularly