fix: ternserver code (#16179)

## Description

Hotfix to resolve `focusedValue` undefined error 
## Type of change

- Bug fix (non-breaking change which fixes an issue)

## How Has This Been Tested?



## Checklist:

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my feature works
- [ ] New and existing unit tests pass locally with my changes

app/client/src/utils/autocomplete/TernServer.ts

@@ -207,7 +207,9 @@ class TernServer {
     }
     const doc = this.findDoc(cm.getDoc());
     const cursor = cm.getCursor();
-    const { extraChars } = this.getFocusedDocValueAndPos(doc);
+    const { extraChars, value: focusedValue } = this.getFocusedDocValueAndPos(
+      doc,
+    );
 
     let completions: Completion[] = [];
     let after = "";