Allow users to add their own ranked Nitro booster role

[patrickklaeren]

When users have ranks above Nitro booster, they are not given the pink colour for boosting. Some prefer this colour. Allow a new command to have users with the Nitro booster role self-assign Ranked Nitro Booster. This is guild specific and should likely be a run option.

Two run options: AllowRankedNitroBoosterRole RankedNitroBoosterRoleId