And other refactorings and fixes

- Collections can be converted into arrays using a mapper and a predicate function

What have I got myself into

- Added support for seat enter and exit events and a test for them
- Added support for entering and exiting seat from code
- Changed the Id property of ECS objects to non-abstract, requiring it in the constructor, so that the Player class can inherit EcsObjectBase
- Added a weird constructor to EcsObjectBase that allows running code to determine the object Id
- Added interface for engines that receive entity functions
- Exposed the entity submission scheduler and removed it from FullGameFields because it moved from there
- Made the Game.Enter event only fire after the first entity submission so the game is fully initialized and the local player exists
- Added all seat groups to the dictionary

- Added a wrapper class that handles the individual wrapping of event handlers to individually handle exceptions - now it tracks the wrapped event handlers so it can unregister them properly
- Fixed an exception that happened when two ECS objects were created with the same EGID
- Added support for returning an existing ECS object if it exists instead of always creating a new one
- Added a parameter to the entity query extension methods to override the group of the ECS object (could be used for the player properties)

Removed old dependencies, including uREPL
Added new block IDs
Implemented basic command handling to support existing mod commands

Also added two port name properties directly to the wires
Also added support for converting OptionalRefs to Nullables

Fixed prefab update for nonexistent blocks
Removed Type from block placed/removed event args
Added test to check the block ID enum (whether it has any extra or missing IDs)
Added test to place every block on the ID enum
Added test to set and verify each property of each block type (type-specific properties are also set when they can be through the API)
Added support for enumerator test methods with exception handling