Move texture editor into inspector

[boxrocket6803]

Summary

Texture editor is just asset browser inspector and preview, all those things are already present in the main editor. This moves the properties from the texture editor window into the normal inspector and completely removes the texture editor tool.

Motivation & Context

Standardizes things a bit, saves having to open a whole separate window.

Implementation Details

There's a lot of stuff in AssetInspector set up specifically for GameResource, I've extended it slightly to allow inspectors to hijack the unsaved changes popup if they provide their own OnSave and OnReset actions.

Screenshots

Checklist

• Code follows existing style and conventions
• No unnecessary formatting or unrelated changes
• Public APIs are documented (if applicable)
• Unit tests added where applicable and all passing
• I’m okay with this PR being rejected or requested to change 🙂

[lolleko]

rest of the changes look okay on first glance, but this seems like a terrible hack

[boxrocket6803]

best as I can tell that's the cleanest way to do it, __fallback is only for game resources, vtex isn't a game resource but should still use that editor (which is just the asset inspector in a window). There isn't really any clean way to differentiate between a non game resource asset that should use the inspector (aka just vtex) and an asset that should open in an external tool/ not open at all

[sboxbot]

This PR has been merged upstream.