Numeric widget and localized number formatting.

[AbdielKavash]

• Replaces text fields where the user is expected to input a number with NumericWidget, supporting extended syntax and formatting. (See Added a numeric widget. ModularUI#62.)
• Replaces instances where a dynamic text field is being communicated between server and client with a purely client-side method. In some cases this allows the client to do localization on these texts correctly. (See Added a text supplier for TextWidget. ModularUI#69.)
• Modifies other instances where the UI displays a number to use a locale-aware formatter. (See Added locale-aware formatting of numbers. ModularUI#67.)

This PR depends on GTNewHorizons/GT5-Unofficial#2532 being merged first, as it is using GT5 classes introduced in the other PR. Marking it as draft until then.