Function remove_coalesce_batches_exec

fn remove_coalesce_batches_exec(
    plan: Arc<dyn ExecutionPlan>,
    fetch: Option<usize>,
) -> Result<Transformed<Arc<dyn ExecutionPlan>>>

Remove CoalesceBatchesExec if the limit is less than the batch size.

so that if limit is too small we can avoid need to scan for more rows than necessary