fix(query): distinct count in user list (#10840)

# Which Problems Are Solved

When listing / searching users, each user got multiplied by the amount
of metadata entries they have, towards the `total_results` count. In
PostgreSQL the `COUNT(*) OVER()` window function does not support
`DISTINCT`. Even tho the query did a distinct select, the count would
still include duplicates.

# How the Problems Are Solved

Wrap the original query in a sub-select, so that the `DISTINCT` gets
handled before the count window function is executed in the outer
function. Filters, permission and solting is applied to the inner query.
Offset, limit and count are applied to the outer query.

# Additional Changes

- none

# Additional Context

- Closes https://github.com/zitadel/zitadel/issues/10825
- Backport to 4v

(cherry picked from commit f27ca69749)

internal/query/search_query.go

@@ -23,6 +23,8 @@ type SearchRequest struct {
 	Limit         uint64
 	SortingColumn Column
 	Asc           bool
+
+	sortingConsumed bool
 }
 
 func (req *SearchRequest) toQuery(query sq.SelectBuilder) sq.SelectBuilder {
@@ -32,15 +34,20 @@ func (req *SearchRequest) toQuery(query sq.SelectBuilder) sq.SelectBuilder {
 	if req.Limit > 0 {
 		query = query.Limit(req.Limit)
 	}
+	return req.consumeSorting(query)
+}
 
-	if !req.SortingColumn.isZero() {
+// consumeSorting sets the sorting column to the query once.
+// subsequent calls will not set the sorting column again.
+func (req *SearchRequest) consumeSorting(query sq.SelectBuilder) sq.SelectBuilder {
+	if !req.sortingConsumed && !req.SortingColumn.isZero() {
 		clause := req.SortingColumn.orderBy()
 		if !req.Asc {
 			clause += " DESC"
 		}
 		query = query.OrderByClause(clause)
+		req.sortingConsumed = true
 	}
-
 	return query
 }