ShadowStrategyGauge::addVestingPosition() may revert if there is 0 liquidity to add
Description:
ShadowStrategyGauge::_addVestingPosition() always tries to mint liquidity, even if it is null. Thus, it may result in reverting, although the chance is extremely low and there isn't any relevant impact as there would be no liquidity to vest anyway (or it is very low).
Recommended Mitigation:
Skip adding liquidity if null.