[Improvement] XMLBuilder Unittest Introduced

Prior to upcoming modifications of the XMLBuilder (FoodContainer merging),
unittest to cover XMLBuilder functionality was added.
[BugFix] Meal Type Displayed Incorrectly

The parser expected the meal type to be the first child of "<td class="popis">"
. Some recent changes to the Sodexo pages introduced other tags prior to meal
type in certain cases, which caused meal type (e.g. Menu 1...) to be displayed
incorrectly (in other words, not to be displayed at all).