Cleanup of old search functionality (#110861)

* Remove support for initMinSize.
Remove support for searchAfterWrite option, now it defaults to true.

* Remove reference to deprecated feature toggle.

* Remove feature toggle completely.

* Remove code related to indexing on watch events.

* Fix compilation error.

* Remove unused field.

pkg/setting/setting_unified_storage_test.go

@@ -35,9 +35,6 @@ func TestCfg_setUnifiedStorageConfig(t *testing.T) {
 		_, err = unifiedStorageSection.NewKey("index_min_count", "5")
 		assert.NoError(t, err)
 
-		_, err = unifiedStorageSection.NewKey("index_max_count", "1000")
-		assert.NoError(t, err)
-
 		cfg.setUnifiedStorageConfig()
 
 		value, exists := cfg.UnifiedStorage["playlists.playlist.grafana.app"]
@@ -52,7 +49,6 @@ func TestCfg_setUnifiedStorageConfig(t *testing.T) {
 
 		// Test that index settings are correctly parsed
 		assert.Equal(t, 5, cfg.IndexMinCount)
-		assert.Equal(t, 1000, cfg.IndexMaxCount)
 	})
 
 	t.Run("read unified_storage configs with defaults", func(t *testing.T) {
@@ -65,6 +61,5 @@ func TestCfg_setUnifiedStorageConfig(t *testing.T) {
 
 		// Test that default index settings are applied
 		assert.Equal(t, 1, cfg.IndexMinCount)
-		assert.Equal(t, 0, cfg.IndexMaxCount)
 	})
 }