bug: improve the weapon spawning mechanism in order for it to become more realistic

[yehiarasheed]

Describe the bug

The problem is, whenever we add a weapon to any of the lanes regardless of the gameplay mode, the weapons spawn in an unrealistic manner where weapons keep spawning in a row, facing the opposite way of the titans till the row is complete to then wrap on to the next row and so on. Such implementation is unrealistic since the intuitive way is to see the first-deployed weapons exactly on the edge of the lane walls facing titans directly, then to fill up the back parts of the lane as the game develops.

To Reproduce

Steps to reproduce the behavior:

1. Start the game using the Start Game button.
2. Click on any of the two Gameplay modes: Easy or Hard.
3. Start adding weapons by navigating to the Weapon Shop in some or all of the game turns by using the Purchase Weapon button, purchasing one of the four weapons using sufficient resources and then choosing a lane using the drop-down menu to deploy the weapon to.
4. See error by checking the lane which you chose to deploy the weapon to.

Expected Behavior

As mentioned earlier, the intuitive way is to see the first-deployed weapons exactly on the edge of the lane walls facing titans directly, then to fill up the back parts of the lane as the game develops.

Describe the solution you'd like

The changes that should fix the issue on hand are: first of all changing the spawning orientation (or adding orientation for the Flowpane used to spawn weapons) such that the weapons spawn vertically instead of horizontally and more importantly is that we invert both the Flowpane and weapon images themselves such that the weapons spawn right in front of the attacking titans and then filling the back parts of the lane as needed.

Screenshots