Added the capacitity to the AssetImportData to resolve a source file name without a loaded package.
This also fixes the issues where the editor is not able to find the source file during a reimport or simply navigating to that file via the content browser.
#jira UE-180553
#rb Kerim.Borchaev
[CL 26609365 by julien stjean in ue5-main branch]
#rb dan.oconnor
#preflight 63d83f963656ea96dc2a0a4c
#jira UE-173747
"Crash occurs when scrolling down through files in Review Changelist window upon loading of asset"
- certain widget blueprints were crashing the review tool because we were working around the inability to diff against nullptr by constructing temprorary empty objects. This approach circumvents that problem entirely
#jira UE-173231
"Changelist Review tool allows diffing against previous revision for Deletion changes"
- while this jira suggests that the ability to diff deletion changes is a bug, it was actually an intended feature. The real bug was that it would crash or fail to work in many cases. This has been fixed by either asset diffing against nullptr or text diffing against an empty file (depending on circumstance)
#jira UE-174610
"Reviewing Changelist with Deletion Changes results in LogLinker warnings & LoadErrors"
- deletion changes were trying to load the new revision of files but obviously it doesn't exist because it's a deletion. Fixed by only loading the previous revision
note: since the review tool is going to be "Production Ready" in 5.2, these changes are neccesary for stability
[CL 23924072 by jordan hoffmann in ue5-main branch]
* Another batch iwyu updates to reduce number of includes used in files
#preflight 63c58d742e714f64ade93797
#rb none
[CL 23732856 by henrik karlsson in ue5-main branch]
AssetDefinition - Changing how getting the SourceFiles works a bit, wanted it to be easier to just get the real data and not have to wrap it myself, and also to not need to needlessly put it into a container if it's not needed.
#jira UE-165574
[CL 23686064 by nick darnell in ue5-main branch]
