Add support for VK_EXT_extended_dynamic_state & VK_EXT_extended_dynamic_state2 extensions.

[billhollings]

• Add MVKRenderingCommandEncoderState to consolidate handling
  of static and dynamic rasterizing states in a consistent manner.

• Rework MVKDepthStencilCommandEncoderState to consolidate handling
  of static and dynamic depth states in a consistent manner.

• MVKMTLDepthStencilDescriptorData clean up content setting, and struct layout.

• Add MVKRenderStateType to enumerate render state types.

• Add MVKRenderStateFlags to track binary info about states (enabled, dirty, etc).

• Add MVKMTLBufferBinding::stride.

• Add `MVKPhysicalDeviceMetalFeatures::dynamicVertexStride.

• Set MVKPhysicalDeviceMetalFeatures::vertexStrideAlignment
  to 1 for Apple5+ GPUs (unrelated).

• Set VkPhysicalDeviceLimits::maxVertexInputBindingStride
  to unlimited for Apple2+ GPUs (unrelated).

• Add mvkVkRect2DFromMTLScissorRect() and simplify
  mvkMTLViewportFromVkViewport() and mvkMTLScissorRectFromVkRect2D().

• MVKFoundation:

  • Add mvkEnableAllFlags( and mvkDisableAllFlags().
  • Improve performance of mvkClear(), mvkCopy() & mvkAreEqual()
    when content is a single simple primitive type (unrelated).
  • Declare more functions as static constexpr (unrelated).

• Add MVKPipelineCommandEncoderState subclasses
  MVKGraphicsPipelineCommandEncoderState & MVKComputePipelineCommandEncoderState,
  track patch control points in MVKGraphicsPipelineCommandEncoderState,
  and add getGraphicsPipeline() & getComputePipeline() to simplify casting.

• Rename `MVKCmdRenderPass.h/mm to MVKCmdRendering.h/mm.

• Move MVKCmdExecuteCommands from MVKCmdRenderPass.h/mm to MVKCmdPipeline.h/mm.

• While working on vkCmdSetLogicOpEXT(), add support for
  vkCmdSetLogicOpEnableEXT() from VK_EXT_extended_dynamic_state3.

Implements primary chunks of #1739 and impacts #1930.

[cdavis5e]

Whew! What a large change!

[spnda]

Will there be an exhaustive list of all the dynamic statea that are "invalidly" unsupported in the MVK documentation? I see some are noted in the original issue on these extension but it doesnt seem up to date anymore.

Otherwise I think everything is covered; though I havent looked thoroughly through the code nor have I tested any of it. Feature compatibility itself is looking good except for the obvious issues with missing required dynamic states.

[billhollings]

Whew! What a large change!

Thanks for all the feedback. I appreciate it.

Will there be an exhaustive list of all the dynamic statea that are "invalidly" unsupported in the MVK documentation?

The list is actually not so exhaustive. There are only two real deviations from conformance (others are actually permitted in the spec via feature flags). I've updated MoltenVK_Runtime_UserGuide.md to document them. In the process, I've structured the extensions section of that document to make it easier to be consistent in specifying limitations for each extension in a readable way, and to encourage us devs to keep that up.

[cdavis5e]

You didn't push anything new for me to review.

[billhollings]

You didn't push anything new for me to review.

Oops! Pushed now.