[FEA] Implement parallel reading of Parquet footers without using the additional thread pool

[vuule]

#17957 optimizes ingest of multiple Parquet files, using an internal thread pool to issue read requests. Parallelism of the read operations is already implemented in kvikIO, so we should not need to launch these reads from multiple threads.

With an async read interface, we could read all footers in a loop from a single thread.