Add separate JSONC language (#12655)

Resolves https://github.com/zed-industries/extensions/issues/860 and
https://github.com/zed-industries/zed/issues/10921, also
https://github.com/biomejs/biome-zed/issues/11.

### Problem:
When opening .json files, zed allows comments by default in the JSON
language, which can cause some problems.
For example, language-servers also get "json" as the language, which may
show errors for those comments.

<img width="935" alt="image"
src="https://github.com/zed-industries/zed/assets/10381895/fed3d83d-abc0-44b5-9982-eb249bb04c3b">

### Solution:

This PR adds a JSONC language. 

<img width="816" alt="image"
src="https://github.com/zed-industries/zed/assets/10381895/8b40e671-d4f0-4e8d-80cb-82ee7c0ec490">

This allows for more specific configuration for language servers. 
Also any json file can be set explicitly to be JSONC using the
file_types setting:

```jsonc
{
  "file_types": {
    // set all .json files to be seen as JSONC
    "JSONC": ["*.json"]
  }
}
```


Release Notes:

- N/A

crates/languages/src/json.rs

@@ -213,7 +213,12 @@ impl LspAdapter for JsonLspAdapter {
     }
 
     fn language_ids(&self) -> HashMap<String, String> {
-        [("JSON".into(), "jsonc".into())].into_iter().collect()
+        [
+            ("JSON".into(), "json".into()),
+            ("JSONC".into(), "jsonc".into()),
+        ]
+        .into_iter()
+        .collect()
     }
 }