Improve goto_file_impl

[TornaxO7]

continues #9038

Closes #8822 #8824

[TornaxO7]

@ModProg

may I ask if you can try it out?

[TornaxO7]

File path detection strategy

I decided to read the chars next to the cursor one by one because:

1. using treesitter requires a parser which doesn't exist for text or log files
   although paths could occur there
2. paths are short enough to be read char by char in my opinion without waiting too
   long

Other information

So I tested it on $HOME/test.txt and ~/test.txt. Both opened up ~/test.txt as expected
but I don't know how to write tests for them.

[ModProg]

I'd consider adding , to the characters terminating a path (like ;).

[TornaxO7]

I'd consider adding , to the characters terminating a path (like ;).

added

[TornaxO7]

I looked that up from neovim. See :h isf in neovim for the list of chars.

[TornaxO7]

I can't execute the integration tests. Executing cargo integration-test gives me:

error[E0412]: cannot find type `Id` in module `tokio::runtime`
  --> helix-event/src/runtime.rs:45:64
   |
45 |         parking_lot::RwLock<hashbrown::HashMap<tokio::runtime::Id, &'static T, ahash::RandomState>>,
   |                                                                ^^ not found in `tokio::runtime`

   Compiling gix-tempfile v13.0.0
error[E0599]: no method named `id` found for struct `Handle` in the current scope
  --> helix-event/src/runtime.rs:67:52
   |
67 |         let id = tokio::runtime::Handle::current().id();
   |                                                    ^^ method not found in `Handle`

Some errors have detailed explanations: E0412, E0599.
For more information about an error, try `rustc --explain E0412`.
error: could not compile `helix-event` (lib) due to 2 previous errors
warning: build failed, waiting for other jobs to finish...

[the-mikedavis]

Thanks!

[the-mikedavis]

For readers' context: rope slicing is by character index rather than byte index (like &str) which is why this uses chars_at(..).count() rather than a len of a substring