[Feature Request]: Preview Formatter Feature Requests

### Feature Description

Hi there,

I've just tried the new Preview Formatter, and for the most part it works great, though I do have some feature requests. I couldn't find an issue for general feedback on the formatter so I'm opening one here.

I'll add my reasoning for the changes I'd like below in case someone wants to take over this issue and add any additional requests.

### Requested Formatter Options
- [ ] New Line After Join Keyword
- [ ] New Line Before On Keyword

### Problem and Motivation

Improve formatter by adding additional options.

### Related Area

- [ ] Connection dialog (SQL Server | Azure browse/Fabric browse)
- [x] Query editor
- [ ] Query results panel
- [ ] Object Explorer
- [ ] GitHub Copilot integration
- [ ] Preview/Edit data
- [ ] Table Designer
- [ ] Schema Designer
- [ ] Schema Compare
- [ ] Local SQL Server Container provisioning
- [ ] SQL database in Fabric provisioning
- [ ] DACPAC/BACPAC export/import
- [ ] SQL Database projects
- [ ] Query Plan Visualizer
- [ ] Other (please describe below)

### If you selected "Other", please describe the area

_No response_

### Confirmation

- [x] I have searched existing feature requests and couldn't find a match
- [ ] I want to help implement this feature

The issue does not name files or tests; start by locating the Preview Formatter implementation and its query-editor option handling. Trace how JOIN and ON keywords are currently formatted, then define completion as supporting the requested newline options and producing the expected query-editor output.

Written by the indexing model from the issue text.