Staker.sol: Shift event emissions to internal functions

[code423n4]

Handle

hickuphh3

Vulnerability details

Impact

The StakeWithdrawalFeeUpdated, MarketLaunchIncentiveParametersChanges, BalanceIncentiveExponentUpdated and BalanceIncentiveEquilibriumOffsetUpdated events are not emitted when addNewStakingFund() is called because they are located in their individual external functions.

Consider shifting the emissions of these events to their internal functions so that addNewStakingFund() will also emit these events.

[JasoonS]

That is done on purpose. It is nicer that they are all emitted in a single event rather than 4 separate messy events.