* HLE: Refactoring of ApplicationLoader

* Fix SDL2 Headless

* Addresses gdkchan feedback

* Fixes LoadUnpackedNca RomFS loading

* remove useless casting

* Cleanup and fixe empty application name

* Remove ProcessInfo

* Fixes typo

* ActiveProcess to ActiveApplication

* Update check

* Clean using.

* Use the correct filepath when loading Homebrew.npdm

* Fix NRE in ProcessResult if MetaLoader is null

* Add more checks for valid processId & return success

* Add missing logging statement for npdm error

* Return result for LoadKip()

* Move error logging out of PFS load extension method

This avoids logging "Could not find Main NCA"
followed by "Loading main..." when trying to start hbl.

* Fix GUIs not checking load results

* Fix style and formatting issues

* Fix formatting and wording

* gtk: Refactor LoadApplication()

---------

Co-authored-by: TSR Berry <20988865+TSRBerry@users.noreply.github.com>

* add RecyclableMemoryStream dependency and MemoryStreamManager

* organize BinaryReader/BinaryWriter extensions

* add StreamExtensions to reduce need for BinaryWriter

* simple replacments of MemoryStream with RecyclableMemoryStream

* add write ReadOnlySequence<byte> support to IVirtualMemoryManager

* avoid 0-length array creation

* rework IpcMessage and related types to greatly reduce memory allocation by using RecylableMemoryStream, keeping streams around longer, avoiding their creation when possible, and avoiding creation of BinaryReader and BinaryWriter when possible

* reduce LINQ-induced memory allocations with custom methods to query KPriorityQueue

* use RecyclableMemoryStream in StreamUtils, and use StreamUtils in EmbeddedResources

* add constants for nanosecond/millisecond conversions

* code formatting

* XML doc adjustments

* fix: StreamExtension.WriteByte not writing non-zero values for lengths <= 16

* XML Doc improvements. Implement StreamExtensions.WriteByte() block writes for large-enough count values.

* add copyless path for StreamExtension.Write(ReadOnlySpan<int>)

* add default implementation of IVirtualMemoryManager.Write(ulong, ReadOnlySequence<byte>); remove previous explicit implementations

* code style fixes

* remove LINQ completely from KScheduler/KPriorityQueue by implementing a custom struct-based enumerator

* Update LibHac to 0.18.0

* Change instance of AsBytes(CreateReadOnlySpan(...)) to AsReadOnlyByteSpan(...)

* IPC refactor part 3 + 4: New server HIPC message processor with source generator based serialization

* Make types match on calls to AlignUp/AlignDown

* Formatting

* Address some PR feedback

* Move BitfieldExtensions to Ryujinx.Common.Utilities and consolidate implementations

* Rename Reader/Writer to SpanReader/SpanWriter and move to Ryujinx.Common.Memory

* Implement EventType

* Address more PR feedback

* Log request processing errors since they are not normal

* Rename waitable to multiwait and add missing lock

* PR feedback

* Ac_K PR feedback

* common: Make BinaryReaderExtensions Read & Write take unamanged types

This allows us to not rely on Marshal.PtrToStructure and Marshal.StructureToPtr for those.

* common: Make MemoryHelper Read & Write takes unamanged types

* Update Marshal.SizeOf => Unsafe.SizeOf when appropriate and start moving software applet to unmanaged types

* hle: Some cleanup

This PR cleaned up a bit the HLE folder and the VirtualFileSystem one, since we use LibHac, we can use some class of it directly instead of duplicate things. The "Content" of VFS folder is removed since it should be handled in the NCM service directly.
A larger cleanup should be done later since there is still be duplicated code here and there.

* Fix Headless.SDL2

* Addresses gdkchan feedback