Get OS and prefill shell with user commands

[ShishirPatil]

• Append command to user bash history and prefill shell. Even though we can append command to bash history, it does not show up in the reverse-i-search without sourcing the shell. This is because the child process cannot modify the environment of the parent caller process stack-overflow reference. So, instead will will pre-fill the shell command with the selected command.
• Get OS environment
• Refactor unique ID generation - mostly cosmetic
• Update server to route LLM based on os environment
• Test on Ubuntu Linux
• Test on Darwin (Mac OS)
• Test on WSL
• Test on Windows Powershell

Thoughts, suggestions, and reviews welcome!

Relevant to #39 and #12

[Buttars]

It would also be nice to be able to edit the command before executing it. Sometimes the LLM gets pretty lose but not perfect and needs some tweaking before being ran. This and the committing to the shell history should likely be behind configuration options. .config/gorilla-cli/config.yml or something similar. Thoughts?

[royh02]

lgtm!