add configurable slot name

[DaemonSnake]

add slot_name configuration option
if not set default to current behaviour (_walex postfix)

other changes include:

• get_configs returns the keywords in the order of the given keys
• add a query builder module and move dependent configs in the start of the Replication.Server

[cpursley]

Merci beaucoup @DaemonSnake!

[cpursley]

@DaemonSnake I'm getting this in my app with these new changes. Any ideas?:

2024-05-03 14:10:57.440 [notice] Application my_app exited: MyApp.Application.start(:normal, []) returned an error: shutdown: failed to start child: WalEx.Supervisor
    ** (EXIT) shutdown: failed to start child: WalEx.Replication.Supervisor
        ** (EXIT) shutdown: failed to start child: WalEx.Replication.Server
            ** (EXIT) :function_clause

[DaemonSnake]

oh sorry didn't see the notification, will look right now
got the error in that past when there was a handle_result that didn't have a matching clause