Upgrading to Entities 1.0.16

[jkeon]

Upgrading the code base to Entities 1.0.16

What is the current behaviour?

Currently on 0.51

What is the new behaviour?

• Removed all [BurstCompatible] and [NotBurstCompatible] attributes.
  • These were actually unit test directives and didn't interface with the Burst compiler.
• No longer allowed to use struct for most generic constraints. Must use unmanaged
• Types use TypeIndex instead of ints
• WorldInternal no longer has OnWorldCreated or OnWorldDestroyed events.
  • Applications can wrap their world creation/destruction to a central location and dispatch their own events or subclass World and handle any specific logic in the Constructor/Dispose method.
• Translation, Rotation, and Scale components no longer exist, instead a LocalTransform component is used.
• Updated Assembly Definitions to remove unneeded references.
• All World.GetOrCreateSystem and related API's are now World.GetOrCreateSystemManaged and related APIs.
• Removed DynamicBufferSharedWriteHandle and the associated bloat that was necessary with WorldCache.
  • This wasn't being used and in practice was better handled by DBFEWriter
• BufferFromEntity is now BufferLookup
• ComponentDataFromEntity is now ComponentLookup
• Most APIs from Unity that used to return NativeArray now return NativeList to account for disabled entities.
  • Related code is now updated to reflect this.
• All IJobEntityBatch are now IJobChunk
• Reworked ParallelAccessUtil since it's now much more simplified.
• Changed ITaskForDefer, ITaskCancelJobForDefer and ITaskUpdateJobForDefer to no longer be generic jobs.
  • Entities 1.0 uses ISystems for Burstable systems and generic job types are no longer allowed.
  • In these jobs, there must be a reader declared in the job and fulfilled by the job data.
  • The Execute function will give an index which can then be used to get the right element from the reader.
  • Updated README

What issues does this resolve?

• None
• While #86 identifies a lot of the work that was done in this PR, the TODO's throughout the code refer to additional work that this PR does not address.

What PRs does this depend on?

• None

Does this introduce a breaking change?

• [x] Yes - Numerous API changes. Projects using this library will also need to migrate application code to Entities 1.0.16
• [ ] No

[jkeon]

Updated based on your comments.

Quite a few of them I had responses for that require your input or an discussion via a call.

Can you check off what is complete in that issue? Or if it makes more sense move the other pending work to new issues.

Yes, updated and checked off everything except for the one remaining effort which is more involved. #86 now refers here and is about going through the code base to create issues for the specific post entities 1.0 upgrade work to do.

[jkeon]

@mbaker3 Additional comments made and/or changes made. Back over to you!