Document weather for static encounters (#3127)

This only matches the weather table with the Pokemon and does not fully
account for whether a location can spawn a particular weather.

Additional minor changes:
- Adds ScriptedNoMarks to Regis and Glimwood Tangle static encounters
- Corrects a few version-specific Pokemon such as Ludicolo/Shiftry
- Removes erroneous encounters such as Milotic in East/West Lake Axewell
- Removes an unused Motostoke Stadium encounter

PKHeX.Core/Legality/Areas/EncounterArea8.cs

@@ -277,6 +277,12 @@ namespace PKHeX.Core
         Heavy_Fog = 1 << 8,
 
         All = Normal | Overcast | Raining | Thunderstorm | Intense_Sun | Snowing | Snowstorm | Sandstorm | Heavy_Fog,
+        Stormy = Raining | Thunderstorm,
+        Icy = Snowing | Snowstorm,
+        All_IoA = Normal | Overcast | Stormy | Intense_Sun | Sandstorm | Heavy_Fog,         // IoA can have everything but snow
+        All_CT = Normal | Overcast | Stormy | Intense_Sun | Icy | Heavy_Fog,                // CT can have everything but sand
+        No_Sun_Sand = Normal | Overcast | Stormy | Icy | Heavy_Fog,                         // Everything but sand and sun
+        All_Ballimere = Normal | Overcast | Stormy | Intense_Sun | Snowing | Heavy_Fog,     // All Ballimere Lake weather
 
         Shaking_Trees = 1 << 9,
         Fishing = 1 << 10,

PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8.cs

@@ -15,6 +15,8 @@ namespace PKHeX.Core
         public byte DynamaxLevel { get; set; }
         public IReadOnlyList<int> Relearn { get; init; } = Array.Empty<int>();
 
+        public AreaWeather8 Weather {get; init; } = AreaWeather8.Normal;
+
         public EncounterStatic8(GameVersion game) : base(game) { }
 
         protected override bool IsMatchLevel(PKM pkm, DexLevel evo)