Implemented tool capabilities

[Whitelisted1]

General Changes

• Implemented tool.py and file.py classes
• Implemented ability to download file in file.py

Refactoring Changes

• Refactored RESPONSE_TYPE_* to class ResponseTypes.*
• Refactored MSGSTATUS_* to class MessageStatus.*
• Renamed some internal variables in next function to be clearer
• Add some short inline comments

Incomplete Features

• With the current setup, the user is unable to get live information about tools that are running, such as when they start and end

Downloading image file example:

out = chatbot.query("Make an image of a computer")
print(out)

file = out.get_files_created()[0]

f = open(f"out.{file.mime.split('/')[1]}", "bw")
f.write(file.download_file(chatbot))
f.close()

[Whitelisted1]

When streaming the content, we now remove the repeated '\u0000' characters that were at the end of each token. This is more of a temporary solution, as we do not know what is causing this, but it should work for now

Solution for #230