V4: Make Variables Manager More Flexible

Describe the Problem Elementor’s Variables Manager currently can’t store unitless numbers (e.g., 1.4). That’s a problem because unitless line-height is [valid CSS]( Right now, if I want to implement a set of constrained values for typography, I have to hardcode line-height per text size in every element, which is super annoying, very easy to desync, and mistype values too. Also, the Variables Manager feels like it’s trying to validate inputs into arbitrary categories (e.g., color, font, size). But really, CSS values are much more diverse, and there are so many more perfectly valid values that this validation excludes, so this validation mechanism ends up restricting a developer's flexibility. Propose a Solution 1. Let size variables store unitless variables 2. Stop hard-blocking values based on variable categories. The UX of the categories is nice. For example, the color wheel is great whenever the value is actually a color, but that shouldn't make it ga…