fix: correctly handle multiple-row insert for SAP HANA driver (#7957)

the SAP HANA SQL dialect does not support inserts with multiple values
but it does support `INSERT ... SELECT` as well as a `SELECT ... FROM dummy`

with that in mind, the `InsertQueryBuilder` has been modified to support
this dialect similar to how we do for Oracle

src/query-builder/InsertQueryBuilder.ts

@@ -484,6 +484,8 @@ export class InsertQueryBuilder<Entity> extends QueryBuilder<Entity> {
                     if (columnIndex === 0) {
                         if (this.connection.driver instanceof OracleDriver && valueSets.length > 1) {
                             expression += " SELECT ";
+                        } else if (this.connection.driver instanceof SapDriver && valueSets.length > 1) {
+                                expression += " SELECT ";
                         } else {
                             expression += "(";
                         }
@@ -597,12 +599,16 @@ export class InsertQueryBuilder<Entity> extends QueryBuilder<Entity> {
                         if (valueSetIndex === valueSets.length - 1) {
                             if (this.connection.driver instanceof OracleDriver && valueSets.length > 1) {
                                 expression += " FROM DUAL ";
+                            } else if (this.connection.driver instanceof SapDriver && valueSets.length > 1) {
+                                expression += " FROM dummy ";
                             } else {
                                 expression += ")";
                             }
                         } else {
                             if (this.connection.driver instanceof OracleDriver && valueSets.length > 1) {
                                 expression += " FROM DUAL UNION ALL ";
+                            } else if (this.connection.driver instanceof SapDriver && valueSets.length > 1) {
+                                expression += " FROM dummy UNION ALL ";
                             } else {
                                 expression += "), ";
                             }