Co-authored-by: Martin Evans <martindevans@gmail.com>

Disable Metal on CI UnitTest

Reintroduce MacOS on CI

- Rewritten native API methods for embeddings to return pointers - null is a valid value for these methods to return so `Span` is not appropriate

* Embeddings correction

Set GPULayerCount to default value (20) to execute UnitTest. In the case of Release Execution on MacOS set the value to ZERO to disable METAL on MacOS and be able to execute it in CI.

Using the new M1 macos runner:

https://github.blog/changelog/2024-01-30-github-actions-introducing-the-new-m1-macos-runner-available-to-open-source/

* Updated binaries, using [this build](https://github.com/SciSharp/LLamaSharp/actions/runs/8654672719/job/23733195669) for llama.cpp commit `f7001ccc5aa359fcf41bba19d1c99c3d25c9bcc7`.

 - Added all new functions.
 - Moved some functions (e.g. `SafeLlamaModelHandle` specific functions) into `SafeLlamaModelHandle.cs`
 - Exposed tokens on `SafeLlamaModelHandle` and `LLamaWeights` through a `Tokens` property. As new special tokens are added in the future they can be added here.
 - Changed all token properties to return nullable tokens, to handle some models not having some tokens.
 - Fixed `DefaultSamplingPipeline` to handle no newline token in some models.

* Moved native methods to more specific locations.

 - Context specific things have been moved into `SafeLLamaContextHandle.cs` and made private - they're exposed through C# properties and methods already.
 - Checking that GPU layer count is zero if GPU offload is not supported.
 - Moved methods for creating default structs (`llama_model_quantize_default_params` and `llama_context_default_params`) into relevant structs.

* Removed exception if `GpuLayerCount > 0` when GPU is not supported.

* - Added low level wrapper methods for new per-sequence state load/save in `SafeLLamaContextHandle`
 - Added high level wrapper methods (save/load with `State` object or memory mapped file) in `LLamaContext`
 - Moved native methods for per-sequence state load/save into `SafeLLamaContextHandle`

* Added update and defrag methods for KV cache in `SafeLLamaContextHandle`

* Updated submodule to `f7001ccc5aa359fcf41bba19d1c99c3d25c9bcc7`

* Passing the sequence ID when saving a single sequence state

Llava Initial approach to clear images

Removed `ContextSize` from most examples

Fixed Beam Search Test

Removed MacOS CI

Disable MacOS CI

- Enabled it in CI

This reverts commit f29f61ee0f.

Extension LLava with in memory images

Added Whisper.net x LLamaSharp examples for Speech Chat