Adds raw flag for vertex and index buffer

[tebjan]

PR Details

Adds the BufferFlags.RawBuffer to relevant instances of index and vertex buffers to allow binding them to compute shaders.

Related Issue

See #1638

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My change requires a change to the documentation.
• I have added tests to cover my changes.
• All new and existing tests passed.
• I have built and run the editor to try this change out.

[tebjan]

The initial approach was too simple and requires more work. Creating raw buffer views involves more than just setting a flag. It requires different flags and formats for the buffer and buffer view, leading to more changes in Stride. To create a raw view, the buffer must be created with D3D11_RESOURCE_MISC_BUFFER_ALLOW_RAW_VIEWS and not combined with other buffer types. This involves using CreateBuffer, CreateShaderResourceView, and CreateUnorderedAccessView with specific flags and structures. These changes are not trivial to implement.

For more details, see Raw Views of Buffers.

Currently thinking about another approach.