initializer modifier should be treated as constructor within ordering rule

[shirotech]

In an upgradable proxy, there is no concept of "constructor", rather they have an initialize function with an initializer modifier. For example:

https://github.com/protofire/solhint/blob/master/lib/rules/order/ordering.js#L142

function initialize() public initializer {
  // initialize member properties here
}

[dbale-altoros]

This is fixed in this pr
#474