Proper handling and sanitizing user inputs when creating game

[Oskarowski]

Description

This pull request addresses two key improvements in the game settings form:

1. Input Validation:

   • Added validation to ensure that the grid size and mines amount are within acceptable ranges on client and server side.
   • Set the maximum grid size to 22x22.
   • Set max mines amount to gridSize * 0.8
   • Implemented checks to handle cases where the user might input excessively large values for grid size, preventing potential server crashes.
   • The max mines amount is dynamically calculated based on grid size and displayed to the user.
   • The mines amount is now validated to ensure it falls within the range of 1 to a maximum determined by the grid size.

2. JavaScript Refactor:

   • Moved JavaScript functions responsible for toggling visibility and adjusting the mines input field range to a separate file.

Found the problem when trying to create the 61st game; the session cookie exceeds its maximum memory value, as described in #9.