Add SQLite ADO.NET schema collections #39190

Microsoft.Data.Sqlite currently does not implement the standard ADO.NET metadata collections exposed through DbConnection.GetSchema(...). For example:

using var connection = new SqliteConnection("Data Source=:memory:");
connection.GetSchema("DataSourceInformation");
// ArgumentException: The requested collection 'DataSourceInformation' is not defined.

This makes SQLite an outlier for provider-agnostic code. SqlClient, Npgsql, and MySqlConnector expose DataSourceInformation and DataTypes, so consumers otherwise have to special-case Microsoft.Data.Sqlite. In particular, pengdows.crud discovers SQLite parameter-marker syntax through DataSourceInformation.

The initial conformance scope should cover the documented common collections: MetaDataCollections, DataSourceInformation, DataTypes, Restrictions, and ReservedWords. Tables, Columns, and Indexes are provider-specific extensions rather than common collections; they may be considered separately if useful for SQLite consumers.

The implementation should use SQLite's documented metadata interfaces and correctly handle attached databases, virtual tables, shadow tables, and user tables whose names begin with sqlite.