refactor: cleanup folder config handling and remove obsolete tests

Simplifies folder configuration handling and removes unnecessary code:

1. Simplified populateFolderConfigs to use stored configs directly instead of creating empty configs and merging
2. Fixed base_scan.go to properly clone all folder config settings when creating config for scanned directory
3. Removed filterFolderConfigs function since filtering happens at source in populateFolderConfigs
4. Updated config_html.go to support Eclipse integration (shows 'Project' label)
5. Removed obsolete tests (TestConfigHtmlRenderer_FiltersFolderConfigsNotInWorkspace and TestConfigHtmlRenderer_NoWorkspaceFiltersAllFolders) that were testing the removed filtering function
6. Kept new TestConfigHtmlRenderer_EclipseShowsProjectSettings test from main
7. Removed skipTrigger parameter and auto-save trigger during initialization in folders.js
8. Improved form-state.js event listener setup for better clarity
9. Fixed createNewStoredConfig to use proper Save function instead of direct Set
10. Improved FolderConfig.Clone() to properly deep clone FeatureFlags and SastSettings