fix: Reset terminate handler directly when being called + some other crashes to crash handling (#1174)

This PR fixes some things about crash handling:
- when the terminate handler is called, immediately set it back to the
original one, so can't make a recursion if the crash-handling code fails
- Only save projects if the crash occured after Imhex finished startup
- do not update the project location when saving the crash backup file:
this will remove problems when `EventAbnormalTermination` is called
before `crashCallback()`

I also added a bit more documentation

lib/libimhex/source/api/project_file_manager.cpp

@@ -17,11 +17,11 @@ namespace hex {
     std::fs::path ProjectFile::s_currProjectPath;
 
     std::function<bool(const std::fs::path&)> ProjectFile::s_loadProjectFunction;
-    std::function<bool(std::optional<std::fs::path>)> ProjectFile::s_storeProjectFunction;
+    std::function<bool(std::optional<std::fs::path>, bool)> ProjectFile::s_storeProjectFunction;
 
     void ProjectFile::setProjectFunctions(
             const std::function<bool(const std::fs::path&)> &loadFun,
-            const std::function<bool(std::optional<std::fs::path>)> &storeFun
+            const std::function<bool(std::optional<std::fs::path>, bool)> &storeFun
     ) {
         ProjectFile::s_loadProjectFunction = loadFun;
         ProjectFile::s_storeProjectFunction = storeFun;
@@ -31,8 +31,8 @@ namespace hex {
       return s_loadProjectFunction(filePath);
     }
 
-    bool ProjectFile::store(std::optional<std::fs::path> filePath) {
-       return s_storeProjectFunction(filePath);
+    bool ProjectFile::store(std::optional<std::fs::path> filePath, bool updateLocation) {
+       return s_storeProjectFunction(filePath, updateLocation);
     }
 
     bool ProjectFile::hasPath() {