Address CR Comments (#132) + Change Core Migration API

This addresses all CR comments including more codebase-wide changes arising from certain review comments like proper usage of its/it's and consistent contraction of it is into it's. 

An overhaul was made to the presentation and formatting of `KThread.h` and `LoadBalance` works has been superseded by `GetOptimalCoreForThread` which can be used alongside `InsertThread` or `MigrateToCore`. It makes the API far more atomic and neater. This was a major point of contention for the design prior, it's simplified some code and potentially improved performance.

app/src/main/cpp/skyline/gpu/texture.h

@@ -150,7 +150,7 @@ namespace skyline {
 
           public:
             std::vector<u8> backing; //!< The object that holds a host copy of the guest texture (Will be replaced with a vk::Image)
-            std::shared_ptr<GuestTexture> guest; //!< The guest texture from which this was created, it is required for syncing
+            std::shared_ptr<GuestTexture> guest; //!< The guest texture from which this was created, it's required for syncing
             texture::Dimensions dimensions;
             texture::Format format;
             texture::Swizzle swizzle;