There are 2 edits here:
1. Remove unnecessarily overridden methods in ElementFinder (they are defined in IThenable).
2. Change the parameterized type in IThenable to 'any' to account for things like ElementFinder.evaluate() which may return primitive values.
The CI build was failing because it tries to compile each file
individually. To fix this I merged all of the files into one. I also
deleted the legacy files since those versions are no longer supported.
* Remove optional parameters from Element interface
* Remove additional parameters from ElementFinder.isElementPresent
* Add "asElementFinders_" and "then" methods to ElementArrayFinder interface