Separated scripts from modules into /scripts

[wu-ming233]

Separated main(args) from the following modules/files:

• src/rank_llm/retrieve/pyserini_retriever.py
• src/rank_llm/analysis/estimate_costs.py
• src/rank_llm/analysis/response_analysis_verbose.py
• src/rank_llm/evaluation/trec_eval.py

Each into a separate file prefixed with run_{file_name} under src/rank_llm/scripts.

Additionally, some lines under demo and rerank were reformatted by black, along with some updates in imports for the separated modules above.

[sahel-sh]

@wu-ming233 thank you for the PR, please resolve the conflicting files.

[wu-ming233]

@wu-ming233 thank you for the PR, please resolve the conflicting files.

Updated!

[wu-ming233]

Removed unnecessary sys path snippets, and incorporated the new PR an hour ago.