Improvements to `/token/owner` endpoint

[DenisCarriere]

Let's work on:

We should be able to do:

1. Account => Owner (with previous owner & current owner)
2. Owner => Accounts (right now too slow, would need a dedicated MV)

For now, let's just hide /token/owner

It's still not really clear to me how we'd offer this data (in a meaningful & performant way)

On-chain behavior

Multiple create/close of the same token account, our data will erase the previous owner on "close"

• Create Account
• Close Account
• Create Account
• Close Account

[DenisCarriere]

Requires changes to Solana Clickhouse DB to add MV's