Use custom errors instead of require statements for gas optimization and clarity

In multiple places in the contract, require statements are used for validation. Consider replacing these with custom errors for gas optimization and improved clarity in error messages.

Affected locations:

• Constructor:

  solidityCopy

  require(_feeRecipient != address(0))

• Deposit function:

  solidityCopy

  require((_shares = super.previewDeposit(assetsNoFee)) != 0, "ZERO_SHARES")

Replace require statements with custom errors. For example:

error ZeroAddress();
error ZeroShares();

// In constructor
if (_feeRecipient == address(0)) revert ZeroAddress();

// In deposit function
if ((_shares = super.previewDeposit(assetsNoFee)) == 0) revert ZeroShares();

This change will save gas and provide more informative error messages.