DbConnectionStringBuilder.ShouldSerialize() doesn't state purpose

### Type of issue

Missing information

### Description

The documentation for the `DbConnectionStringBuilder.ShouldSerialize()` method looks like a copy and paste of the documentation on the `DbConnectionStringBuilder.ContainsKey()` method.

A bit more clarity on the purpose of the method and how it is diffeent from `.ContainsKey()` would be useful for implementers.

My best guess is that the `ShouldSerialize()` method is intended to check if a key is valid for the ADO.NET client implementing the specialized connection string builder from the perspective that unsupported keys do not have to be serialized when the connection string builder *serializes* its key/value dictionary into a string.

If that's the case, I would suggest the following documentation (*which, just in case, I hereby declare to have just written myself in this browser window and which I offer freely and for use for any purpose, including modification, re-licensing and inclusion in differently-licensed works*)

```csharp
///
/// Allows the database-specific ADO.NET provider's specialized connection string builder inheriting
/// from this class to indicate whether the specified key is supported by that ADO.NET provider.
///
/// The key to check for support by the specific ADO.NET provider
///
/// True if the ADO.NET provider recognized and supports the specified key, false otherwise
///
///
/// This method can be used to sanitize connection strings and to avoid confusion by removing any
/// keys for options that an ADO.NET provider does not support anyway, but which the user may
/// believe to have some effect for the database connection
///
public virtual bool ShouldSerialize(string keyword) { /* ... */ }
```

### Page URL

https://learn.microsoft.com/en-us/dotnet/api/system.data.common.dbconnectionstringbuilder.shouldserialize?view=net-9.0

### Content source URL

https://github.com/dotnet/dotnet-api-docs/blob/main/xml/System.Data.Common/DbConnectionStringBuilder.xml

### Document Version Independent Id

ff1c22c0-fe31-1d68-eb45-9305d6725db7

### Article author

@dotnet-bot