MsSqlMessageQueue logs the full connection string, including the password, at Debug

`src/Paramore.Brighter.MessagingGateway.MsSql/SqlQueues/MsSqlMessageQueue.cs:34`:

```csharp
Log.MsSqlMessageQueueCtor(s_logger, _configuration.ConnectionString, _configuration.QueueStoreTable);
```

and the message template at `:254`:

```csharp
[LoggerMessage(LogLevel.Debug, "MsSqlMessageQueue({ConnectionString}, {QueueStoreTable})")]
```

A SQL Server connection string routinely carries `Password=...`. At `Debug` this reaches every configured sink — console, file, and whatever aggregator the application ships to.

### Why it matters more than it used to

The MSSQL messaging gateway's own documentation now tells a reader to put a password in that string, and the sample under `samples/TaskQueue/MsSqlMessagingGateway` demonstrates it. That sample keeps the credential off stdout **only** because `GreetingsSender` happens to set `MinimumLevel.Override` for this category — a mitigation that works for one sample and for nobody else. Anyone running Brighter at `Debug` gets the password in their logs.

This was raised independently by three separate review rounds on #4331, which is usually a sign the fix belongs in the library rather than in another README paragraph.

### Suggested fix

Log the server and database without the credential — `SqlConnectionStringBuilder` gives you `DataSource` and `InitialCatalog` directly:

```csharp
var builder = new SqlConnectionStringBuilder(_configuration.ConnectionString);
Log.MsSqlMessageQueueCtor(s_logger, builder.DataSource, builder.InitialCatalog, _configuration.QueueStoreTable);
```

That keeps everything the log line is actually useful for — which server, which database, which table — and drops the part nobody wanted in a log. The sample's `MinimumLevel.Override` and the README's warning about it could then both be deleted rather than maintained.

Start in src/Paramore.Brighter.MessagingGateway.MsSql/SqlQueues/MsSqlMessageQueue.cs at the constructor log call and the LoggerMessage template around line 254. Inspect the sample under samples/TaskQueue/MsSqlMessagingGateway and the README warning. Done means logs retain server, database, and table context without exposing the connection-string password, and the sample override and warning are removed.

Written by the indexing model from the issue text.