Add ability to create a Scheduled event with Not A Bot twitch stream detection

[Elanis]

This PR adds API to use Scheduled events and create them if needed when a Twitch stream begins.

Changelog:

• Add API endpoints/enums for scheduled events
• Expose those endpoints to the bot
• Create an event if ShouldCreateDiscordEvent is checked in TwitchConfig
• Event duration is CreateDiscordEventDuration or 3600 by default

Events examples:

Tested with a custom command as I can't test real twitch notifications.

The custom command:

    self:RegisterCommand({
        Name = "testa",
        Silent = false,
        Args = {
        },
        Help = "Test things",
        Func = function(commandMessage, channel)
            commandMessage:reply("ok")

            commandMessage.guild:createScheduledEvents(
                enums.scheduledEventsEntityTypes.external,
                string.format("https://twitch.tv/%s", "elanis42"),
                "Test title",
                enums.scheduledEventsPrivacyLevel.guild_only,
                os.date("!%Y-%m-%dT%TZ", os.time() + 1),
                os.date("!%Y-%m-%dT%TZ", os.time() + 3600)
            )
        end
    })