[WIP] Add `getEventStats`

[MonsieurBibo]

Here is the draft PR of the getEventStats method in order to close #509.

It takes data from https://www.hltv.org/stats/players?event=EVENT_ID

• [X] getEventStats method added
• [X] Optional flash, opening and pistol stats to reduce the amount of requests made to the API.
• [x] Parameters like startDate, endDate, or side
• [x] ⚠️ Use user config instead of default one
• [ ] Proper Types
• [ ] Tests
• [ ] Improve performance (maybe array splice ?)

[MonsieurBibo]

It might be good to rename the method as getEventPlayersStats or else because other stats are also available for events.

[MonsieurBibo]

Well I'm dumb, everything is almost already implemented in getPlayerStats method. What is only needed is to modify the existing method.

[gigobyte]

Cleaning up, please open a new pull request if you feel like finishing this feature.