Accept file drop events when loading begins, not after

Version and Platform (required):

• Binary Ninja Version: 3.4.4149-dev
• OS: macOS
• OS Version: 12.4
• CPU Architecture: M1

Bug Description:
When you drag and drop a file onto binja, the os event for dropping the files is not accepted until the file loads successfully. This is done to not accept drops of files that cannot be loaded. For small files, this is not an issue, but for larger files, this leaves your file browser ui waiting as it is stuck in the drag sequence. On macos, this effectively freezes finder until it times out after like 15 seconds. Binja should accept the drop event immediately if the file can even try to be parsed, as waiting too long looks like the file could not be parsed anyway.

Steps To Reproduce:

1. Open binja
2. Find a large file in finder (like a huge bndb or binary)
3. Drag and drop into binja
4. Observe file drag event get very stuck

Expected Behavior:
I expected drag and drop events to not time out

Additional Information:
Might only be a macOS behavior. I haven't tested on other platforms.

Start by locating the macOS file-drop handling path in Binary Ninja and trace when the drop event is acknowledged relative to file loading. Reproduce with a large bndb or binary, then verify that the event is accepted as soon as parsing can be attempted rather than after loading completes.