unformat() {
        this._setElementValue(this.getNumericString());

        return this;
    }
Remove the formatting and keep only the raw unformatted value in the element (as a numericString)
Note: this is loosely based on the previous 'unSet()' function

By default, values are returned as ISO numeric strings (i.e. "1234.56" or "-1234.56"), where the decimal character is a period.
@example anElement.unformat()

@returns {AutoNumeric}