Lay out and drive the depot browser the way the old starter did

Picking a category picks its first class and lists that class, instead of
every vehicle of the category; only categories with something in them are
offered, in the old order. The archival switch has its own line, the class
box shows the thumbnail of the class picked, and the search sits above the
list and looks through every vehicle. The rows are the bare texture names, a
set marked faintly; an empty list says what to do; the thumbnail and Add
share a line so the list keeps its height.

StarterNG/startercfg/lang/en.xml

@@ -95,6 +95,9 @@
     <String key="Crew">with crew</String>
     <String key="Reversed">reversed</String>
     <String key="NoVehicles">No vehicles found in dynamic/**/textures.txt.</String>
+    <String key="BrowserHint">Pick a category or type a vehicle's name.</String>
+    <String key="BrowserNoMatch">Nothing matches “{0}”.</String>
+    <String key="SearchAllVehicles">Search all vehicles…</String>
     <String key="ConsistEmpty">Add vehicles from the database on the left, or load an existing consist from a scenery file.</String>
     <String key="TipMoveLeft">Move left</String>
     <String key="TipMoveRight">Move right</String>