List block trades
Get a paginated list of block trades with filtering.
Returns block trades where user is initiator, required signer,
or has submitted an offer.
**Filters:**
- Status: CREATED, OFFER_COLLECTION, READY_TO_EXECUTE, EXECUTING, COMPLETED, CANCELLED
- Market: Specific market symbol (e.g., BTC-USD-PERP)
**Returns:** Paginated list with block trade details and navigation metadata.