Fix null byte error in cli_tools_click.py

[ShyamSathish005]

Fixes #69

Resolve the syntax error 'source code string cannot contain null bytes' in src/google/adk/cli/cli_tools_click.py.

• Remove null byte:

  • Remove null byte from the source code string in the main function.
  • Ensure the import process completes successfully without any syntax errors.

• Update docstrings:

  • Correct and reformat docstrings for cli_run, eval, web, api_server, and cloud_run functions to remove null bytes and improve readability.

• Reformat code:

  • Reformat code blocks to ensure proper indentation and alignment.
  • Reformat import statements within the eval function to ensure proper module imports.