[Feat] (DirectVulkan): upload combined depth-stencil texture data

UploadDirtyMipLevels used to skip D24S8/D32FS8 textures outright, leaving
glTexImage-supplied depth-stencil data unuploaded (KHR-GL33
texture_repeat_mode depth24_stencil8 and texture_swizzle depth-stencil
cases all sampled zeros). De-interleave the shadow's GL wire format into a
depth plane (X8_D24 word / float) and a stencil byte plane and record one
copy per aspect, with cross-conversion when the device backs the texture
with the other depth-stencil format.

Depth32FStencil8's shadow byte size also claimed 16 bytes/texel while the
stored wire format (GL_FLOAT_32_UNSIGNED_INT_24_8_REV) is 8; that mismatch
truncated every upload of it.

Also route a multisample-texture sample-count request through the device's
supported counts (round up, GL promises at-least semantics).

MobileGL/MG_Backend/DirectVulkan/Renderer/VkTextureManager.h

@@ -481,6 +481,9 @@ private:
     std::unordered_map<TextureIdentity, TextureResource, TextureIdentityHash> m_textureResources;
     // Textures that have been bound to a GL image unit (see MarkStorageImageTexture).
     std::unordered_set<TextureIdentity, TextureIdentityHash> m_storageImageTextures;
+    // Supported multisample counts per format, so repeat texture syncs do not
+    // re-query vkGetPhysicalDeviceImageFormatProperties.
+    std::unordered_map<VkFormat, VkSampleCountFlags> m_multisampleCountsByFormat;
     Vector<Vector<TextureResource>> m_deferredReleases;
     Vector<Vector<VkImageView>> m_deferredViewReleases;
     // Texture uploads are submitted out-of-band but NOT waited on (waiting