[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_Util/Metrics/TextureMetrics.cpp

@@ -91,6 +91,9 @@ namespace MobileGL {
             case TextureInternalFormat::RG32F:
             case TextureInternalFormat::RG32I:
             case TextureInternalFormat::RG32UI:
+            // Shadow bytes hold the GL_FLOAT_32_UNSIGNED_INT_24_8_REV wire format
+            // (float depth + a word whose low 8 bits are stencil), 8 bytes/texel.
+            case TextureInternalFormat::Depth32FStencil8:
                 return 8;
 
             case TextureInternalFormat::RGB32F:
@@ -101,7 +104,6 @@ namespace MobileGL {
             case TextureInternalFormat::RGBA32F:
             case TextureInternalFormat::RGBA32I:
             case TextureInternalFormat::RGBA32UI:
-            case TextureInternalFormat::Depth32FStencil8:
                 return 16;
 
             case TextureInternalFormat::R11FG11FB10F: