Add support for lazy connections in R2DBC in the same manner as LazyConnectionDataSourceProxy

[cloudshiftchris]

Support lazy connections in R2DBC following the same concepts in LazyConnectionDataSourceProxy for JDBC.

atm hitting an "empty" transaction (the calls are cached so no actual database operations are performed) still borrows a connection from the pool, starts the connection and commits the transaction.

2024-11-15T14:15:16.436-08:00 DEBUG 8774 [atcher-worker-9] io.r2dbc.mssql.QUERY                     : Executing query: SELECT 1
2024-11-15T14:15:16.447-08:00 DEBUG 8774 [actor-tcp-nio-5] io.r2dbc.mssql.QUERY                     : Executing query: BEGIN TRANSACTION ****;
2024-11-15T14:15:16.449-08:00 DEBUG 8774 [actor-tcp-nio-5] io.r2dbc.mssql.QUERY                     : Executing query: IF @@TRANCOUNT > 0 COMMIT TRANSACTION;

(the SELECT 1 is the connection pool validation query)