[Feature Request]: Add schema-level filtering to Schema Compare Feature

### Feature Description

Enable users to exclude all objects in one or more schemas when running Schema Compare in the VS Code MSSQL extension.

This feature would add a “Schema” filter in the Options dialog, similar to existing object-type filters, to let users toggle entire schemata on or off before comparison.

### Problem and Motivation

Most database objects are synchronized across my environments, but I maintain certain schemas with environment-specific objects.

Currently, every object in those schemas appears in Schema Compare and must be manually unchecked or excluded one by one, which is time-consuming and error-prone when dozens of objects exist.

Providing schema-level exclusion would streamline the workflow, reduce mistakes, and make it easier to focus on real differences.

### Related Area

- [ ] Connection dialog
- [ ] Query editor
- [ ] IntelliSense/auto-completion
- [ ] Query results panel
- [ ] Object Explorer
- [ ] Table Designer
- [x] Schema Compare
- [ ] Schema Designer
- [ ] 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

Start by locating the Schema Compare implementation and its Options dialog in the TypeScript extension; no files or tests are named in the issue. Trace how existing object-type filters are represented and applied, then verify that selecting schemas to exclude removes their objects from comparison results.

Written by the indexing model from the issue text.