Allow extensions to provide data for language_ids (#10053)

This PR makes it so extensions can provide values for the `language_ids`
method on the `LspAdapter` trait.

These are provided as data in the `language_servers` section of the
`extension.toml`, like so:

```toml
[language_servers.intelephense]
name = "Intelephense"
language = "PHP"
language_ids = { PHP = "php"}
```

Release Notes:

- N/A

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

crates/extension/src/extension_manifest.rs

@@ -1,5 +1,5 @@
 use anyhow::{anyhow, Context, Result};
-use collections::BTreeMap;
+use collections::{BTreeMap, HashMap};
 use fs::Fs;
 use language::LanguageServerName;
 use semantic_version::SemanticVersion;
@@ -99,6 +99,8 @@ pub struct GrammarManifestEntry {
 #[derive(Clone, PartialEq, Eq, Debug, Deserialize, Serialize)]
 pub struct LanguageServerManifestEntry {
     pub language: Arc<str>,
+    #[serde(default)]
+    pub language_ids: HashMap<String, String>,
 }
 
 impl ExtensionManifest {