Tracking Issue for Config UI & API Improvements #3385

PR that fixes some of these aspects: #3397

Potential Improvements to be made

• Indicate pages that open external screens more clearly in the page list, by an icon, text, or both
• Make scrollbars thicker for easier use
• Hide search bar clear button when nothing is searched
• Make search bar text have more contrast
• Inset the whole UI into a centered container of reasonable width on large screens
• When inset, space between search bar/close button and page list/search bar?
• Disabled tickboxes don't show the right enablement state
• per-option and global reset by holding down shift
• Clicking on mod headers in the page list should jump to the start of their options in the option list
  - [ ] Clicking on mod headers in the page list should collapse the page list, in conflict with the previous suggestion. This could also collapse the version information. However, it's bad UX to have two similar elements (mod headers and page headers) in the page list cause such different behaviors.
• moving the window from one monitor to the other while the settings ui is open causes a crash because it tries to read a video mode with an index higher than the number of video modes on the new screen
• Adjust spacing in multiple places in the UI to accomodate horizontal and vertical external margins on the content area (separately)
• Use left/right bouncy text or widen the options to account for some locale requiring more width. Bouncy text is just not nice to look at while widening the options is problematic since on small screens doing so is impossible. We could potentially widen the options slightly only when there's enough space (i.e. instead of adding an inset to the sides, we first widen the options by maybe 40% at most)
• Pressing the escape key when there are pending changes should perform "undo", and then pressing it again should exit the screen.
• Option text is cut off when italic
• Reconsider the size of the reset button's click target. On iris it's the whole option width, though I don't find this behavior intuitive.
• The scrollable tooltips' scroll bar appears to be broken when the tooltips are shown inline

API Improvements

• Custom update flags (like renderer reload) and registering flag-related runners globally
• Post-save hooks that are syntactic sugar for a unique flag per option example
• API for mods to open the config screen and jump to a certain page for use in mod menu integrations. example
• Document Option Overlay and Replacement API usage
• Graphics presets to match vanilla
• Customization of presents? Adding new presets? adding options from mods to presets through the api?
• Allow other mods to hide existing options (such as when they become inapplicable for some reason due to the other mod's changes to the game)
• Allow other mods to insert their options in a specific place, review usecase
• Allow other mods to define the order in which they appear in the sidebar
• Consider design for more flexible enum options that don't have predefined values, as per the suggestion here.