Provide an ability to configure a retry policy

[Unnamed1984]

Currently the RetryPolicy class is internal, ShardMapManagerFactory.GetSqlShardMapManager accepts RetryBehavior which doesn't allow to change RetryPolicy anyhow.

[Unnamed1984]

Also you say that it has a built in list of transient errors to handle:

But it doesn't, the predicate always returns false:

[stuartpa]

I'm moving the library to the now native to SqlClient retry logic:

https://learn.microsoft.com/en-us/sql/connect/ado-net/configurable-retry-logic?view=sql-server-ver16