Make .bat and .cmd editors work on windows

[pm100]

This Pull Request fixes/closes #1316.

This has several parts

• first it adds code to enable .bat and .cmd commands to be invoked without the .bat or .cmd being given (core.editor='vim' will now run vim.bat)
• it then adds unit tests
• it also reorganized some code used for testing in asyncgit so that it can be used in the main, gitui, product

The actual fix is fairly straightforward.

• if on windows and the configured editor fails to launch then retry
• retry using cmd /C <editor> <file>
• if that fails to start or cmd reports an error then report that to the user

The reorg needs an explanation

• open_file_in_editor need a repo.
• there is test plumbing in asyncgit that provides many repo utilities
• sadly things declared 'test' are not available in other products / subcrates. But there is a solution. see make code compiled with cfg(test) visible across crates rust-lang/cargo#8379. It involves creating a test-utils feature and making that a dev dependency.
• That now makes that test plumbing in asyncgit/sync/mod.rs no longer hidden under a test umbrella. The exhaustive cliuppy, lints, cargo-sort etc now picks up all sorts of issues there (that really dont matter) so now I had to add in a few things to stop those being picked up. Note that they are still only being compiled when doing tests, its just that clippy 'all-features' doesnt realize that

I also note that there are no other external editor test cases. I will add more once I get this in (I willl look at #1654 and put them in the fix for that). I did add one generic test, but there should be more

I followed the checklist:

• [ x] I added unittests
• [x ] I ran make check without errors
• [x ] I tested the overall application
• I added an appropriate item to the changelog

[extrawurst]

this is a red-flag. why do we want that? it bloats the binary. did you investigate what introduces the multiple versions of the same crate?

[extrawurst]

see above

[pm100]

Multiple versions do not get built into the product, they only happen on test builds

cargo clippy --workspace --all-features complains about the code that is in the test feature 'test_utils'. It does not realize that this is only for testing

Same for cargo deny

I tried real hard to untangle the multiple versions even though it only really happens with tests. I could not untangle some of them (people who version their crate 0.xx are very annoying because 0.45 is not seen as a valid replacement for 0.44 by cargo. Yes windows-sys we are looking at you)

Then I saw that you already had the ignore dups in main.rs and in deny.toml and decided OK its not just me that could not un ravel these

TL;DR - the dups only happen when running tests

[pm100]

I had to do a quick commit with that allow taken out because I could not remember what actually failed, I knew it was part of the CI build

[pm100]

I just discovered squash. I apologize for my messy prs. I will clean this up