New system of block and cross pose and auto focus on the puzzle selector

Hello, an important update for the game feel. I was asked several times so here it is after a few days of work on it.

Update :

- Linear pose: The pose of blocks and crosses is now restricted to one row or column with each click held. This avoids to make a mistake when you move a lot. If you "go back" with your mouse, the previous state of the boxes will be automatically restored. Only the release of the held click confirms the pose.

- Auto placement of blocks : This avoids having blocks that do not place when you go faster than the number of frames per second

- Non priority of the poses : A block pose can't overwrite a cross anymore

- Auto-focus puzzle selector : The puzzle selection is automatically placed at the last puzzle done

Every feedback is appreciated and thanks for reading!