Fix networking batch handling, wallet scan timeouts, payments API validation, and startup responsiveness

[QuickMythril]

Summary:

• Ensure batched GET_BLOCK replies go to all requesters.
• Process all BLOCK_SUMMARIES_V2 messages without early exit and start schedulers immediately.
• Validate required params in payments-between API to avoid 500s.
• Prevent Electrum timeouts from causing under-reported balances; increase history timeout.

Fix GET_BLOCK batching to respond to all requesters

• File: src/main/java/org/qortal/controller/Controller.java
• Change: Group GET_BLOCK requests by signature and send cached/fetched/archive/unknown responses to every requesting peer instead of overwriting duplicates.
• Fixes: Peers asking for the same uncached block at the same time no longer get dropped/responses lost.

Process all BLOCK_SUMMARIES_V2 batch messages

• File: src/main/java/org/qortal/controller/Controller.java
• Change: Replace early returns in the BLOCK_SUMMARIES_V2 batch loop with continue, so all queued summaries are processed.
• Fixes: Peers weren’t getting chain-tip updates if an earlier message failed.

Validate confirmationStatus for payments-between API

• File: src/main/java/org/qortal/api/resource/TransactionsResource.java
• Change: Add null check for confirmationStatus and return INVALID_CRITERIA instead of NPE/500.
• Fixes: Calling /transactions/payments/between without confirmationStatus no longer crashes.

Avoid treating Electrum timeouts as empty history in wallet scan

• File: src/main/java/org/qortal/crosschain/Bitcoiny.java
• Change: Introduce tri-state result for async history checks and don’t advance gap on timeouts; only on confirmed empty history.
• Fixes: Prevents wallet address scanning from stopping early and under-reporting balances when Electrum servers are slow.

Increase history timeout for Electrum address scans

• File: src/main/java/org/qortal/crosschain/Bitcoiny.java
• Change: Raise transaction-history check timeout to 15s (keep others at 10s).
• Fixes: Reduces false timeouts that could still lead to extra scanning or missed addresses.

Start GET_BLOCK and BLOCK_SUMMARIES_V2 schedulers immediately

• File: src/main/java/org/qortal/controller/Controller.java
• Change: Remove the 60s initial delay on the batch schedulers (start at 0s, run every second).
• Fixes: Node responds to block/summary requests immediately after startup instead of waiting a minute.