Reenable get_client method on testcontainers feature

[Snapstromegon]

What is this task about?

Right now the get_client method of the testcontainer feature in #3 is disabled since the client doesn't exist yet.
Task is to reenable that method once the client exists.

What needs to be done to complete this task?

• Implement basic client
• Uncomment crate::container::Container::get_client https://github.com/thenativeweb/eventsourcingdb-client-rust/pull/3/files#diff-afdac8a4ddf3c241511c938601d995c42b63feb59dcc2ab122ed6d2d67fd4283R171-R179

What else should we know?

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