Add new make-file-executable API for extensions (#10047)

This PR adds a new function, `make-file-executable`, to the Zed
extension API that can be used to mark a given file as executable
(typically the language server binary).

This is available in v0.0.5 of the `zed_extension_api` crate.

We also reworked how we represent the various WIT versions on disk to
make it a bit clearer what the version number entails.

Release Notes:

- N/A

---------

Co-authored-by: Max <max@zed.dev>

crates/extension_api/wit/since_v0.0.4/extension.wit

@@ -62,9 +62,12 @@ world extension {
     /// Gets the latest release for the given GitHub repository.
     import latest-github-release: func(repo: string, options: github-release-options) -> result<github-release, string>;
 
-    /// Downloads a file from the given url, and saves it to the given filename within the extension's
+    /// Downloads a file from the given url, and saves it to the given path within the extension's
     /// working directory. Extracts the file according to the given file type.
-    import download-file: func(url: string, output-filename: string, file-type: downloaded-file-type) -> result<_, string>;
+    import download-file: func(url: string, file-path: string, file-type: downloaded-file-type) -> result<_, string>;
+
+    /// Makes the file at the given path executable.
+    import make-file-executable: func(filepath: string) -> result<_, string>;
 
     /// Updates the installation status for the given language server.
     import set-language-server-installation-status: func(language-server-name: string, status: language-server-installation-status);