perf: make prover able to certify more than 5 transactions

Some SQL query was too complex because depended on the number of block
ranges to retrieve in the prover. The query is now made indiviudally on
each block range.

Author: jpraynaud

mithril-aggregator/src/dependency_injection/builder.rs

@@ -1377,7 +1377,7 @@ impl DependenciesBuilder {
         Ok(self.message_service.as_ref().cloned().unwrap())
     }
 
-    /// build Prover service
+    /// Build Prover service
     pub async fn build_prover_service(&mut self) -> Result<Arc<dyn ProverService>> {
         let mk_map_pool_size = self
             .configuration

mithril-aggregator/src/services/prover.rs

@@ -106,10 +106,14 @@ impl MithrilProverService {
         block_ranges: &[BlockRange],
     ) -> StdResult<HashMap<BlockRange, Vec<CardanoTransaction>>> {
         let mut block_ranges_map = HashMap::new();
-        let transactions = self
-            .transaction_retriever
-            .get_by_block_ranges(block_ranges.to_vec())
-            .await?;
+        let mut transactions = vec![];
+        for block_range in block_ranges {
+            let block_range_transactions = self
+                .transaction_retriever
+                .get_by_block_ranges(vec![block_range.clone()])
+                .await?;
+            transactions.extend(block_range_transactions);
+        }
         for transaction in transactions {
             let block_range = BlockRange::from_block_number(transaction.block_number);
             let block_range_transactions: &mut Vec<_> =