Basic example via database/sql driver

Basic example demonstrates the possibilities of YDB with database/sql driver:

• create/drop tables with scheme query mode
• upsert data with data query mode
• select with data query mode (unary request ExecuteDataQuery in native ydb-go-sdk)
• select with scan query mode (streaming request StreamExecuteScanQuery in native ydb-go-sdk)
• explain query mode for getting AST and Plan of query processing
• modify transaction control
• different types of query args:
  • multiple sql.NamedArg (uniform database/sql arg)
  • multiple native (for ydb-go-sdk) table.ParameterOption which constructs from table.ValueParam("name", value)
  • single native (for ydb-go-sdk) *table.QueryParameters which constructs from table.NewQueryParameters(parameterOptions...)