Add ability to specify binary path/args for rust-analyzer (#9293)

This fixes #9292 by adding a section to the language server settings
that allows users to specify the binary path and arguments with which to
start up a language server.

Example user settings for `rust-analyzer`:

```json
{
  "lsp": {
    "rust-analyzer": {
      "binary": {
        "path": "/Users/thorstenball/tmp/rust-analyzer-aarch64-apple-darwin",
        "arguments": ["--no-log-buffering"]
      }
    }
  }
}
```

Constraints:

* Right now this only allows ABSOLUTE paths.
* This is only used by `rust-analyzer` integration right now, but the
setting can be used for other language servers. We just need to update
the adapters to also respect that setting.



Release Notes:

- Added ability to specify `rust-analyzer` binary `path` (must be
absolute) and `arguments` in user settings. Example: `{"lsp":
{"rust-analyzer": {"binary": {"path": "/my/abs/path/rust-analyzer",
"arguments": ["--no-log-buffering"] }}}}`
([#9292](https://github.com/zed-industries/zed/issues/9292)).

Co-authored-by: Ricard Mallafre <rikitzzz@gmail.com>

crates/extension/src/extension_lsp_adapter.rs

@@ -19,7 +19,7 @@ pub struct ExtensionLspAdapter {
     pub(crate) host: Arc<WasmHost>,
 }
 
-#[async_trait]
+#[async_trait(?Send)]
 impl LspAdapter for ExtensionLspAdapter {
     fn name(&self) -> LanguageServerName {
         LanguageServerName(self.config.name.clone().into())