[SERVICES-2541] Timescaledb query for token mini price charts

[mad2sm0key]

Reasoning

• the priceCandles query and the underlying timescaleDB aggregate are set for deprecation

Proposed Changes

• add specialized tokensLast7dPrice query that can return price candles (with a 4 hours resolution) for multiple tokens in a single request
• add timescaleDB query for fetching token prices from the token_candles_hourly aggregate
• add manual gapfilling logic
• add cache warmer + resolve query from cached values

How to test

query {
  tokensLast7dPrice(
    identifiers: ["WEGLD-bd4d79", "HTM-f51d55", "MEX-455c57", "BOBER-9eb764"]
  ) {
    identifier
    candles {
      time
      ohlcv
    }
  }
}