Implement Series tab

[dzenbot]

The idea is to list all the ongoing Series, their races and leaderboard, to give wider exposure to this feature. This should go hand-by-hand with promoting chapter races and point races for championships (ProSpec, etc).

We will need new API endpoints for this:

• series/list: List all the active Series
• series?id: Get the Series by id, which includes metadata such as pic, description, start & finish dates, class, format, race count, pilot count, etc.
• race/list?series=id: List all the Races from a specific Series
• series/standings?series=id: List all the Results from a specific Series. This should be a combined list of User objects + individual results