Export theme data to QML

As a QT developer
I can have theme data as a QML file
so I can more easily adopt HIG design in my app

---

### Acceptance criteria

#### Export one QML file per theme

Theme files will be accessible at this path within the published NPM package.
```
`@hig/theme-data/qml/darkGrayHighDensityTheme.qml`
```

#### Format role names using camel case
E.g. `paddingSmall` in `property int paddingSmall: 2`

#### Format widths as unit-less `int` and `real`
As in this example:
```
property int iconHoverSizeBump: 4
property real iconHoverScale: 1.15
```

#### Format colors as hex and alpha hex
As in this example:
```
property color higStateColorNormal: "#f5f5f5"
property color higStateColorNormal50: "#80ffffff"
```

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### Open questions

- Can teams consume QML via NPM?

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See an [example of a QML file](https://git.autodesk.com/lorenzh/qml-toolbar-prototype/blob/master/qml/ToolbarView/ToolbarStyle.qml)

Start by locating the existing theme-data package layout and the entry point that generates or publishes theme files; the issue names no source file or test. Check whether @hig/theme-data can publish QML through NPM, then verify that each theme produces a QML file with camel-case roles, unitless int/real values, and hexadecimal colors as specified.

Written by the indexing model from the issue text.