Add score mode to canvas

Score mode will allow customers to set up scores for dropdowns and multi-select, where, for each option, they can set a score (weight), which can be used in conditional split and show in results page. We are going to have a general setup mode, a toggle on top of the form that says "Score mode". When ticked to yes, it allows the user to set scores/weights for options. We need to be able to use this score in the conditional split: the score will be calculated until the point of conditional split node. If it's not at the end of the form and it's used somewhere in the middle, the score until that node will be used we need to add a score column, if score mode is activated, in results page too The column can be used in filters and sorting, so it needs to be integrated in mellisearch