Return None if field is missing in Airtable record

[onimsha]

This pull request includes changes to improve code readability and robustness in the backend/danswer/prompts/prompt_utils.py file. The most important changes involve reformatting import statements and updating the way employee context information is retrieved.

Code readability improvements:

• backend/danswer/prompts/prompt_utils.py: Reformatted import statements to use parentheses for better readability.

Code robustness improvements:

• backend/danswer/prompts/prompt_utils.py: Updated the employee_context string construction to use the get method, providing a default value of None if the key is not present in the dictionary.