Add composite fields to aggregation (#8518)

## Context
This PR introduces a first aggregation for a composite field

## Test
<img width="1074" alt="Screenshot 2024-11-15 at 15 37 05"
src="https://github.com/user-attachments/assets/db2563f9-26b7-421f-9431-48fc13bce49e">

packages/twenty-server/src/engine/api/graphql/workspace-schema-builder/utils/get-available-aggregations-from-object-fields.util.ts

@@ -19,6 +19,7 @@ export type AggregationField = {
   type: GraphQLScalarType;
   description: string;
   fromField: string;
+  fromSubField?: string;
   aggregationOperation: AGGREGATION_OPERATIONS;
 };
 
@@ -79,6 +80,16 @@ export const getAvailableAggregationsFromObjectFields = (
       };
     }
 
+    if (field.type === FieldMetadataType.CURRENCY) {
+      acc[`avg${capitalize(field.name)}AmountMicros`] = {
+        type: GraphQLFloat,
+        description: `Average amount contained in the field ${field.name}`,
+        fromField: field.name,
+        fromSubField: 'amountMicros',
+        aggregationOperation: AGGREGATION_OPERATIONS.avg,
+      };
+    }
+
     return acc;
   }, {});
 };