feat: introduce mega to raid stats

[Fabio1988]

This will add mega information to raid stats

conflicts on migration with #348 , be careful with any testing

[ccev]

I've been running this for the day and can confirm it's working fine.

fyi: old raids are all set to temp_evo_id = 0, whereas mega raids should obviously have a value there. Personally, I just set temp_evo_id for all level 6 raids to 1. There's other raid levels too that have megas, so consider those if you care. This is "made up" data and does not account for mega forms, so a migration should not be part of Golbat.

#348 discusses this query a little. I just did this:

CREATE TEMPORARY TABLE tmp_merge_raid AS
SELECT date, area, fence, level, pokemon_id, form_id, 1 AS temp_evo_id, SUM(count) AS count
FROM raid_stats
WHERE level = 6
GROUP BY date, area, fence, level, pokemon_id, form_id;

DELETE FROM raid_stats WHERE level = 6;

INSERT INTO raid_stats SELECT * FROM tmp_merge_raid;

DROP TABLE tmp_merge_raid;