MergeUI does not include SET IDENTITY_INSERT <tablename> ON prior to MERGE statements that perform INSERTs

When I use MergeUI to generate insert + update + delete statements, and the table I generate the statement for has an IDENTITY column, I get a MERGE statement that contains an INSERT

```sql
WHEN NOT MATCHED BY TARGET THEN INSERT ([id],...
```
But here id is an IDENTITY column, so that fails with the error:

```
[S0001][544] Cannot insert explicit value for identity column in table '' when IDENTITY_INSERT is set to OFF.
```
I could surround the MERGE statement with the statement to allow INSERTs

```sql
SET IDENTITY_INSERT ON

SET IDENTITY_INSERT OFF
```
But that somehow feels wrong, since the tool itself knows already that it has to generate inserts. I think MergeUI itself should surround SET IDENTITY_INSERT.