Add support for sprite object (#1488)

## Launch Checklist

- Fixes #1302

When a sprite object is used, the current settings modal does not
present it well and does not allow editing.
This changes the input from a string to json.
It does make the editing a bit more cumbersome as you need to type `"`
now instead of just placing the address, but if you click the info
button you should be able to understand that this is a special field.
The fact that it looks like a code editor should also help guide users
to place different input there.

Before:
<img width="710" height="297" alt="image"
src="https://github.com/user-attachments/assets/a615dddd-6c06-45fb-b5a9-1820e6a5c077"
/>


After:
<img width="710" height="297" alt="image"
src="https://github.com/user-attachments/assets/fdb89ada-91ca-4bf4-8380-ce3c25373b41"
/>


 - [x] Briefly describe the changes in this PR.
 - [x] Link to related issues.
- [x] Include before/after visuals or gifs if this PR includes visual
changes.
 - [x] Write tests for all new functionality.
 - [ ] Add an entry to `CHANGELOG.md` under the `## main` section.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

src/components/modals/ModalSettings.tsx

@@ -11,6 +11,8 @@ import FieldSelect from "../FieldSelect";
 import FieldEnum from "../FieldEnum";
 import FieldColor from "../FieldColor";
 import Modal from "./Modal";
+import FieldJson from "../FieldJson";
+import Block from "../Block";
 import fieldSpecAdditional from "../../libs/field-spec-additional";
 import type {OnStyleChangedCallback, StyleSpecificationWithId} from "../../libs/definitions";
 
@@ -144,13 +146,13 @@ class ModalSettingsInternal extends React.Component<ModalSettingsInternalProps>
           value={(this.props.mapStyle as any).owner}
           onChange={(value) => this.changeStyleProperty("owner", value)}
         />
-        <FieldUrl
-          fieldSpec={latest.$root.sprite}
-          label={t("Sprite URL")}
-          data-wd-key="modal:settings.sprite"
-          value={this.props.mapStyle.sprite as string}
-          onChange={(value) => this.changeStyleProperty("sprite", value)}
-        />
+        <Block label={t("Sprite URL")} fieldSpec={latest.$root.sprite} data-wd-key="modal:settings.sprite">
+          <FieldJson
+            lintType="json"
+            value={this.props.mapStyle.sprite as any}
+            onChange={(value) => this.changeStyleProperty("sprite", value)}
+          />
+        </Block>
 
         <FieldUrl
           label={t("Glyphs URL")}