Add the openingExplorerLichess for master/lichess games

[tiyn]

In the official Lichess API documentation there is a paragraph about the openingExplorerLichess.

These features of the opening explorer for master and lichess games seem pretty useful so it would be great if these endpoints get added:

• https://explorer.lichess.ovh/master
• https://explorer.lichess.ovh/lichess

[Virinas-code]

I'm working on it. See #38.