Add summary flag to CLI and add scan_directory function to Python

[Speedrunyourknowledge]

Description

When the user runs Magika in the CLI, they now have the option of providing a --summary flag.
If this flag is active (and the --json flag is not active), then Magika's normal output will be followed by a list of detected file types and their count.

When the user runs Majika in Python, they can now use the scan_directory function, which takes in 2 parameters: directory and recursive_scan. Adding a directory tells the function to scan all the files in the directory, and setting recursive_scan to True tells the function to recursively scan all subdirectories in the directory.

Implementation

Updated rust/cli/src/main.rs to keep track of how many times each file type was detected.
Configured the summary list to display in order of descending file count, followed by alphabetical order.

Added a new scan_directory function to python/src/magika/magika.py.
Added a unit test to python/tests/test_magika_python_module.py.
Added relevant test files to tests_data/directory.

Screenshots

CLI: Output of cargo run -- --recursive --summary ../../tests_data

Python: Printing the list returned by magika.scan_directory(tests_data, True)

• File path is on the left, and file type is on the right