[FEATURE] DB Rename trading → crypto_trading

[jovirecall]

Continuation from #929

The "core" competitions table in apps/api has a single "type" field, which is always a "trading" string value. we can migrate this to crypto_trading.

Also, the preceding frontend PR introduced a new method that maps "trading" => "crypto trading". We'll want alter the formatCompetitionType method and remove the custom mapping. However, we can keep the fn and make it: convert the original type value from snake_case to Title Case.