Feature Request: Added Trigger to Update Vehicle Actual Mileage

[StPfeffer]

Description

Created a trigger to update the vehicle actual_mileage based on the total_distance of a new route.

Type of change

• [x] New feature (non-breaking change which adds functionality)

Checklist

• [x] I ran cargo clippy --all -- -D warnings just before my last commit and fixed any issue that was found.
• [x] I ran cargo fmt --all -- --check just before my last commit.
• [x] I ran cargo test just before my last commit and all tests passed.
• [x] I added my algorithm to the corresponding mod.rs file within its own folder, and in any parent folder(s).