CsvSpawner - fix spawning when the terrain is included

[w-czerski]

About:

This PR introduces improvement to the CsvSpawner.
❌ Removed frame skipping and counting
✅ Rely on built in Bus Notifies in AzFramework::Terrain

Entities are spawned based on Terrain availability.
If not available- call SpawnEntities() in first available frame (like it was done before).

Component Type	Improvement Description
Game Component	If Terrain exists - spawn will be called upon OnTerrainCreateEnd(), otherwise queue spawn on activation.
Editor Component	If Terrain exists - spawn will be called upon OnTerrainDataChanged(), otherwise queue spawn on activation. Editor has dedicated masks to filter important updates, that indicate is terrain created properly - so call happens only once.

Why use different events?

• OnTerrainCreateEnd() - notifies when Terrain is Activated, launched at finish.
• OnTerrainDataChanged - notifies every time when Terrain Data has changed inside Tick.

Terrain is being initiated not only in Activate(), but OnTick(). This generates some problems while being in Editor.
Since physics don't work the same way as in game mode, editor needs another approach. It is possible to filter every Terrain updates with masks (flags), and SpawnEntities() when Terrain is ready.

Features (in Editor)

Terrain is not available in the level	Terrain is available in the level

• SpawnOnEditorConfig: Spawns entities when the level is loaded (on activation).
• SpawnOnTerrainUpdate: Spawns entities when the terrain is updated, such as when terrain is moved, its transform is changed, terrain system settings are altered, or the terrain is regenerated. It also adjusts spawned entities to reflect these changes.
• TerrainFlagsToIgnore: Filter masks that prevent unwanted updates of terrain in the editor before spawning. You can keep SpawnOnTerrainUpdate enabled and specify which updates should trigger entity spawning.

Example

1. On level opened, entities will be spawned. Changes made to terrain settings and color data won't trigger spawn entities.

SpawnOnEditorConfig = ON
SpawnOnTerrainUpdate = ON
TerrainFlagsToIgnore = {Settings + Color Data}

2. On level opened, entities won't be spawned. Changes made to any terrain settings, data, transform will trigger update spawn entities.

 SpawnOnEditorConfig = OFF
 SpawnOnTerrainUpdate = ON
 TerrainFlagsToIgnore = {None}

3. On level opened, entities will be spawned. Any changes made to terrain won't spawn entities. Automatically - Terrain Flags are set to ignore all masks.

 SpawnOnEditorConfig = ON
 SpawnOnTerrainUpdate = OFF
 TerrainFlagsToIgnore = {All}

[w-czerski]

Also please note, that solution in editor Reflcet of Enums TerrainChangedDataMask is a dirty hack. I couldnt manage o3de to work with AZStd::vector<TerrainChangedDataMask> - it always resulted in crash. If you have any solution for this, let me know.

[patrykantosz]

Few minor comments.