Add com.snowplowanalytics.snowplow/mobile_context/jsonschema/1-0-3

[matus-tomlein]

This is a new version of the mobile_context schema tracked by the mobile trackers which will add the following properties:

• isPortrait – A Boolean indicating whether the device orientation is portrait (either upright or upside down)
• resolution – Screen resolution in pixels. Arrives in the form of WIDTHxHEIGHT (e.g., 1200x900)
• scale – Scale factor used to convert logical coordinates to device coordinates of the screen (uses UIScreen.scale on iOS and DisplayMetrics.density on Android)
• language – System language currently used on the device (ISO 639)

The resolution, scale, and language properties are added to reflect the new browser_context on Web (#1249) which moves some of the canonical properties from the events to the context entity. This is another step on the path to deprecate the canonical properties and unify the Web and mobile data models.