First version of unit handling: canonicalizing on input

Customizations/JSON/UnitConfigJson.ts

@@ -0,0 +1,36 @@
+export default interface UnitConfigJson{
+
+    /**
+     * The canonical value which will be added to the text.
+     * e.g. "m" for meters
+     * If the user inputs '42', the canonical value will be added and it'll become '42m'
+     */
+    canonicalDenomination: string,
+
+    /**
+     * A list of alternative values which can occur in the OSM database - used for parsing.
+     */
+    alternativeDenomination?: string[],
+
+    /**
+     * The value for humans in the dropdown. This should not use abbreviations and should be translated, e.g.
+     * {
+     *     "en": "meter",
+     *     "fr": "metre"
+     * }
+     */
+    human?:string | any
+
+    /**
+     * If set, then the canonical value will be prefixed instead, e.g. for '€'
+     * Note that if all values use 'prefix', the dropdown might move to before the text field
+     */
+    prefix?: boolean
+
+    /**
+     * The default interpretation - only one can be set.
+     * If none is set, the first unit will be considered the default interpretation of a value without a unit
+     */
+    default?: boolean
+
+}