Edits to chunking blast function

[golu099]

1. Arguments Added: Function now takes in -taxidlist argument to fine tune taxonomic profile during BLAST run
2. Error Handling: Added a try/finally block in the get_hits_pipe function for better resource cleanup.
3. Enhanced Logging: More detailed messages and elapsed time measurements.
4. Chunking Logic: Improved chunk size calculation by considering base_reads_per_chunk and remainder_reads. Removed old logic involving chunk_max_size_per_threads and simplified chunk size adjusment. Now function prioritizes at least 4 threads per blast run, reducing runtime especially in larger datasets. Additionally, number of chunks never surpasses maximum number of workers at any point. Instead in these scenarios, larger chunks are constructed.