Source MSSQL: MSSQL Named Instance with CDC

### Connector Name

mssql

### Connector Version

1.0.16

### What step the error happened?

During the sync

### Revelant information

We have a SQL Server Named Instance.
When configuring the source, we specify the following hostname:
`.internal.example.com\`
The port is typically 38000.

This works perfect for the non-cdc source. When we use CDC though, we get the following error:
```
INFO i.a.i.d.i.DebeziumRecordPublisher(lambda$start$1):74 Connector configuration is not valid. The 'database.hostname' value is invalid: ourinstance.internal.example.com\TST_Gen1 has invalid format (only the underscore, hyphen, dot and alphanumeric characters are allowed)
```

The error is correct. The problem is that debezium expects the instance name (TST_Gen1 in my example) in the `database.instance` attribute and not as part of the hostname:
https://debezium.io/documentation/reference/stable/connectors/sqlserver.html#sqlserver-property-database-instance

Thus, we should either add an `Instance Name` field to the Source configuration mask, or parse the \ from the hostname.

### Relevant log output

```shell
INFO i.a.i.d.i.DebeziumRecordPublisher(lambda$start$1):74 Connector configuration is not valid. The 'database.hostname' value is invalid: ourinstance.internal.example.com\TST_Gen1 has invalid format (only the underscore, hyphen, dot and alphanumeric characters are allowed)
```

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