patterns: GVAS pattern for Unreal Engine 4+ games (#522)

* patterns: GVAS pattern for Unreal Engine 4+ games

* delegate test

* fengineversion format

* Show enums in custom versions

* Improve property parsing

* Support more types

* Organize

* Support more types

* EEditorObjectVersion::AddedAlwaysSignNumberFormattingOption

* Vector2D

* GameplayTagContainer

* DateTime, Guid, IntPoint, LinearColor, Timespan

* More UE naming convention

* Support more text types

* Support old ETextHistoryType::None

* VER_UE4_FTEXT_HISTORY

* Improve PROPERTY_TAG_COMPLETE_TYPE_NAME support

* cleanup

* Collapse newlines

* Fix format_fstring for UTF-16 strings

Author: scottanderson

README.md

@@ -119,6 +119,7 @@ Everything will immediately show up in ImHex's Content Store and gets bundled wi
 | Gold Box Games: Map | | [`patterns/GoldBox/GB_GEO.hexpat`](patterns/GoldBox/GB_GEO.hexpat) | Gold Box Game Map files |
 | Gold Box Games: Unlimited Adventures Script | | [`patterns/GoldBox/GB_UA_SCRIPT.hexpat`](patterns/GoldBox/GB_UA_SCRIPT.hexpat) | Gold Box Unlimited Adventures SCRIPT file |
 | Gold Box Games: Vault | | [`patterns/GoldBox/GB_VLT.hexpat`](patterns/GoldBox/GB_VLT.hexpat) | Gold Box Game Vault files |
+| GVAS | | [`patterns/gvas.hexpat`](patterns/gvas.hexpat) | Unreal Engine 4+ Save Game file |
 | GZIP | `application/gzip` | [`patterns/gzip.hexpat`](patterns/gzip.hexpat) | GZip compressed data format |
 | Halo Tag || [`patterns/hinf_tag.hexpat`](patterns/hinf_tag.hexpat) | Halo Infinite Tag Files |
 | Halo Module || [`patterns/hinf_module.hexpat`](patterns/hinf_module.hexpat) | Halo Infinite Module Archive Files |