Feature/cache transparency 121

[intagliated]

Adds cache transparency features as requested in issue #121.

Changes Made

• Added --show-cache-info CLI option to display cache location and total size in MB
• Added --clear-cache CLI option to remove all cached satellite imagery
• Removed exists=True validation from samples_path to allow cache options to run without a valid CSV
• Cache size is calculated recursively and shown with warning when exceeding 500MB
• Cache location is displayed during prediction operations

Testing

# Show cache information
cyfi predict --show-cache-info

# Clear all cached imagery  
cyfi predict --clear-cache

# Use custom cache directory
cyfi predict samples.csv --cache-dir ./my_cache

[ejm714]

This PR won't be reviewed until you remove all the extraneous files