language servers: Fix wrong language server name (#20428)

This fixes the issue of multiple language servers showing up as `node`
in the language server logs dropdown.

It does this by changing `language_server.name()` to return the
adapter's name, not the binary name, and changing types to make sure
that we always use this.

Release Notes:

- Fixed language server names showing up only as `"node"`

---------

Co-authored-by: Sam Rose <hello@samwho.dev>
Co-authored-by: Bennet <bennet@zed.dev>

crates/extension/src/extension_manifest.rs

@@ -1,7 +1,8 @@
 use anyhow::{anyhow, Context, Result};
 use collections::{BTreeMap, HashMap};
 use fs::Fs;
-use language::{LanguageName, LanguageServerName};
+use language::LanguageName;
+use lsp::LanguageServerName;
 use semantic_version::SemanticVersion;
 use serde::{Deserialize, Serialize};
 use std::{