Minor improvements and fixes to streamlit webserver

Minor improvements and fixes to Streamlit webserver:

Do not send logs to front end: Needs fixing; Leaks between sessions. Would need to create separate loggers per session with specific context that can be filtered before being sent to front end.
Log each run, with number of uploaded peptides
Clean error message on invalid peptide csv upload
Styled download button
Show current package versions in sidebar
Fixed help tooltip formatting
Added README

compomics / DeepLC