[FEAT] Add a hex/ascii editor style preview for binary files without a differ/viewer

[mjfs]

It would save a lot of time if SourceGit would support a hex/ascii editor style preview as other git GUI clients do when reviewing a repository history. This way one can at least quickly decipher the errors of incorrect extensions being committed and other file format classification errors (e.g. executable, video, etc.) without actually opening the file.

[love-linger]

Because the cost of viewing content of a binary file is a little expensive:

• We must save it to a temp file first since:
  • it may be different from the file in current worktree
  • it may be very large so we can not load it to a memory stream
• We must clear the created temp file in time
• We may not want to view the content of all binary files

So SourceGit requires an extra click to open builtin hex-viewer

[love-linger]

Now, we also support to view the content of binary file in NEW side (right-side in diff) in binary diff view.