Relocates the error code to where it's most related, similar to how all
the other error codes are. Previously we were including a non-generic
error in the main result code header.

Removes a few inclusion dependencies from the headers or replaces
existing ones with ones that don't indirectly include the required
headers.

This allows removing an inclusion of core/memory.h, meaning that if the
memory header is ever changed in the future, it won't result in
rebuilding the entirety of the HLE services (as the IPC headers are used
quite ubiquitously throughout the HLE service implementations).

Keeps filesystem-related error codes in one spot.

Many containers within the standard library provide different behaviors
based on whether or not a move constructor/assignment operator can be
guaranteed not to throw or not.

Notably, implementations will generally use std::move_if_noexcept (or an
internal implementation of it) to provide strong exception guarantees.
If a move constructor potentially throws (in other words, is not
noexcept), then certain behaviors will create copies, rather than moving
the values.

For example, consider std::vector. When a std::vector calls resize(),
there are two ways the elements can be relocated to the new block of
memory (if a reallocation happens), by copy, or by moving the existing
elements into the new block of memory. If a type does not have a
guarantee that it will not throw in the move constructor, a copy will
happen. However, if it can be guaranteed that the move constructor won't
throw, then the elements will be moved.

This just allows ResultVal to be moved instead of copied all the time if
ever used in conjunction with containers for whatever reason.

* Add and correct some Error Modules

Avoids doing work that doesn't need to be done.

Replace it with std::move(result_val).Unwrap(), or Foo().Unwrap() in
case you already have an rvalue.

It is now known that result code description vary depending on the
module, and so they're best defined on a per-module basis. To support
this, allow passing in an arbitrary integer instead of limiting to the
ones in the ErrorDescription enum. These will be gradually migrated to
their individual users, but a few will be kept as "common" codes shared
by all modules.

Reduce the associated port's connection count when a ServerSession is destroyed.

The error code was taken from the 3DS kernel.

ExtSaveData is more similar to SaveData, so let it be a subclass of SaveData

The error checking of SaveDataArchive is completely different from DiskArchive, so it has to be a new class instead of a subclass of DiskArchive.

This makes clang-format useful on those.

Also add a bunch of forgotten transitive includes, which otherwise
prevented compilation.

Format information is currently only implemented for the ExtSaveData, SharedExtSaveData and SaveData archives, the information is stored in a file alongside the root folder of the archive.

These operations are limited by the open flags specified while opening the file.