remove underscore (#4069)

* removed some of the underscore methods in web3-core-method

* removed underscore from bzz

* adding subscriptions

* fixing up test cases

* changing variable names

* removed underscore from formatters.js

* removed underscore from request manager and abi

* removing underscore in the rest of the web3 packages

* fixing exports

* fixing failing testcases

* removing underscore from tests

* addressing feedback

* removing unwanted code from transaction

* removing underscore from remaining packages

* updating change log

* addressing feedback

* adding strict equality

* efficient short circuiting

* fixing test case