fix: Fix compound relational filters in aggregates (#2297)

## Relevant issue(s)

Resolves #1869

## Description

Fixes compound relational filters in aggregates where their dependencies
were not already part of the query.

planner/mapper/mapper.go

@@ -370,6 +370,19 @@ func resolveAggregates(
 				mapping.SetChildAt(index, childMapping)
 
 				if !childIsMapped {
+					filterDependencies, err := resolveFilterDependencies(
+						ctx,
+						store,
+						childCollectionName,
+						target.filter,
+						mapping.ChildMappings[index],
+						childFields,
+					)
+					if err != nil {
+						return nil, err
+					}
+					childFields = append(childFields, filterDependencies...)
+
 					// If the child was not mapped, the filter will not have been converted yet
 					// so we must do that now.
 					convertedFilter = ToFilter(target.filter.Value(), mapping.ChildMappings[index])

tests/integration/query/one_to_one/with_count_filter_test.go

@@ -16,8 +16,6 @@ import (
 	testUtils "github.com/sourcenetwork/defradb/tests/integration"
 )
 
-// This test documents a bug and should be altered with:
-// https://github.com/sourcenetwork/defradb/issues/1869
 func TestQueryOneToOneWithCountWithCompoundOrFilterThatIncludesRelation(t *testing.T) {
 	test := testUtils.TestCase{
 		Description: "One-to-one relation with count with _or filter that includes relation",
@@ -103,17 +101,12 @@ func TestQueryOneToOneWithCountWithCompoundOrFilterThatIncludesRelation(t *testi
 				}`,
 				Results: []map[string]any{
 					{
-						"_count": "2",
+						"_count": int(2),
 					},
 				},
 			},
 		},
 	}
 
-	testUtils.AssertPanic(
-		t,
-		func() {
-			testUtils.ExecuteTestCase(t, test)
-		},
-	)
+	testUtils.ExecuteTestCase(t, test)
 }