Flappybird security

[Riad-Attou]

Add security for score submission with key verification in flappybird

Previously, intercepting requests allowed users to modify scores.
Now, an additional security layer with a key mechanism ensures
scores cannot be modified with during transmission.

This commit goes hand-in-hand with the related changes in Titan.

[Daihecyy]

See the section on linting and formatting to allow your code to pass : https://github.com/aeecleclair/Hyperion?tab=readme-ov-file#linting-and-formating
Remember to also edit the tests to ensure they still pass.
Since you implemented new behavior, it would be best if a new test reflected that.
Otherwise, great job !