Eventuous breaks with npgsql >= 7.0.0

[fbjerggaard]

When trying to use the Postgres event store along with npgsql >= 7.0.0 it breaks with the following exception:

Npgsql.PostgresException (0x80004005): 42883: procedure eventuous.read_all_forwards(_from_position => bigint, _count => integer) does not exist

The workaround is to put the following code somewhere (I put it above the services.AddAggregateStore<PostgresStore>();):

AppContext.SetSwitch("Npgsql.EnableStoredProcedureCompatMode", true);

The real solution would probably be something like rewriting this (and other similar methods):

eventuous/src/Postgres/src/Eventuous.Postgresql/Subscriptions/PostgresAllStreamSubscription.cs

Lines 24 to 31 in b4f1af7

	protected override NpgsqlCommand PrepareCommand(NpgsqlConnection connection, long start) {
	var cmd = new NpgsqlCommand(Schema.ReadAllForwards, connection);
	cmd.CommandType = CommandType.StoredProcedure;
	cmd.Parameters.AddWithValue("_from_position", NpgsqlDbType.Bigint, start + 1);
	cmd.Parameters.AddWithValue("_count", NpgsqlDbType.Integer, Options.MaxPageSize);
	return cmd;
	}

into just using the recommended plain method which is SELECT * FROM function_name($1,$2)

Source: https://www.npgsql.org/doc/release-notes/7.0.html#a-namecommandtypestoredprocedure-commandtypestoredprocedure-now-invokes-procedures-instead-of-functions

Another issue is that connections to the database are not reused/not closed which is probably related to the new DbDataSource way of connecting: https://www.npgsql.org/doc/release-notes/7.0.html#dbdatasource