Add editor font size settings

[CopeFiend]

Closes #910

Description

Add options for configuring font size in Editor UI.

Progress

• Add font_size option to Settings Window -> General
• Modify Editor font size through font_size option
• Store modified value in settings.ron
• Clamp value in Settings Window (8.0px - 48.0px)
• Handle text widgets with previously hard-coded values (World Viewer, Tilemap Property, etc.)
• Handle layout scaling with large fonts

Review Guidance

• Most Builders now have the following fields and methods:

pub font: Option<FontResource>, // Default: None
pub font_size: Option<StyledProperty<f32>>, // Default: None

pub fn with_font(mut self, font: FontResource) -> Self {
   self.font = Some(font);
   self
}

pub fn with_font_size(mut self, font_size: StyledProperty<f32>) -> Self {
   self.font_size = Some(font_size);
   self
}

• Every instance of Builder now explicitly calls the with_font() and with_font_size() methods
• Would like to whether putting everything in Settings::general is a wise decision.

Screenshots/GIFs

WIP

Checklist

• My code follows the project's code style guidelines
• I have commented my code, particularly in hard-to-understand areas
• I have updated the documentation accordingly
• My changes don't generate new warnings or errors
• No unsafe code introduced (or if introduced, thoroughly justified and documented)

[mrDIMAS]

I'm not quite sure why there's a need to add this huge heap of additional methods. What I'd do is to just modify standard style's variable and called ui.set_style. This will propagate all the changes to all widgets that handles text. Also, for now the editor uses this FONT_SIZE variable almost everywhere, so it is basically uses the same font size for every widget.

For places that has different font size, I'd just add a separate style variable, specific to the place where it belongs. Then it can be modified and ui.set_style can be called.

To proportionally change the font size for every styled variable I'd change the type of FONT_SIZE variable to a new type called FontSize and after that it'd be possible to iterate over all such properties in the style and scale them accordingly. So basically: take the default style, create its copy, scale all the FontSize properties accordingly, then call ui.set_style. This should be enough.

Of course, I might be missing some issues. Let's discuss this.

[CopeFiend]

@mrDIMAS Created a Discussion thread #915 , with replies to feedback #915 (comment) .