Improve SessionBuilder ergonomy and fix clippy errors

[gabotechs]

This PR redesigns the SessionBuilder interface into a more simple one: the DistributedSesssionBuilder, with just 1 method instead of 3.

Now building a Session for an ArrowFlightEndpoint is driven completely by the user, and they can either implement the trait themselves:

#[async_trait]
impl DistributedSessionBuilder for MySessionBuilder {
    async fn build_session_state(
        &self,
        ctx: DistributedSessionBuilderContext,
    ) -> Result<SessionState, DataFusionError> {
        Ok(SessionStateBuilder::new()
            .with_runtime_env(ctx.runtime_env.clone())
            .with_default_features()
            .build())
    }
}

or just the function shorthand

// Any function with this signature automatically implements the `DistributedSessionBuilder` trait
fn build_state(ctx: DistributedSessionBuilderContext) -> Result<SessionState, DataFusionError> {
    Ok(SessionStateBuilder::new()
        .with_runtime_env(ctx.runtime_env.clone())
        .with_default_features()
        .build())
}

---

This PR also addresses the clippy errors failing in the pipelines

[robtandy]

This looks great! I'm glad to see ergonomic improvements in the user facing API. This is a clear step forward.