WIP settings system.

- updated dbdiagrams schema
- [BREAKING] force failure if `notify.filter_attributes` or `notify.level` is set
- added Settings table (and default values during migration)
- Added Save Settings and Get Settings functions.
- Added web API endpoints for getting and saving settings.
- Deprecated old Notify* constants. Created new MetricsStatus* and MetricsNotifyLevel constants.

webapp/backend/pkg/database/scrutiny_repository_settings.go

@@ -0,0 +1,33 @@
+package database
+
+import (
+	"context"
+	"fmt"
+	"github.com/analogj/scrutiny/webapp/backend/pkg/models"
+)
+
+func (sr *scrutinyRepository) GetSettings(ctx context.Context) (*models.Settings, error) {
+	settingsEntries := []models.SettingEntry{}
+	if err := sr.gormClient.WithContext(ctx).Find(&settingsEntries).Error; err != nil {
+		return nil, fmt.Errorf("Could not get settings from DB: %v", err)
+	}
+
+	settings := models.Settings{}
+	settings.PopulateFromSettingEntries(settingsEntries)
+
+	return &settings, nil
+}
+func (sr *scrutinyRepository) SaveSettings(ctx context.Context, settings models.Settings) error {
+
+	//get current settings
+	settingsEntries := []models.SettingEntry{}
+	if err := sr.gormClient.WithContext(ctx).Find(&settingsEntries).Error; err != nil {
+		return fmt.Errorf("Could not get settings from DB: %v", err)
+	}
+
+	// override with values from settings object
+	settingsEntries = settings.UpdateSettingEntries(settingsEntries)
+
+	// store in database.
+	return sr.gormClient.Updates(&settingsEntries).Error
+}