Plugins: Add preinstall_sync config - allow plugins to be preinstalled synchronously (#105292)

* feat: preinstall_sync config - process and installation logic

* ref: add preinstall_sync list to preinstalled plugins of frontendsettings

* fix: conf blank line for sections

* ref: remove plugins async flag, and rename PreinstallPlugins

* docs: default installed plugin list

pkg/services/pluginsintegration/pluginchecker/checker.go

@@ -11,7 +11,7 @@ func ProvidePreinstall(
 	cfg *setting.Cfg,
 ) *PreinstallImpl {
 	plugins := make(map[string]*setting.InstallPlugin)
-	for _, p := range cfg.PreinstallPlugins {
+	for _, p := range cfg.PreinstallPluginsAsync {
 		plugins[p.ID] = &p
 	}
 	return &PreinstallImpl{

pkg/services/pluginsintegration/pluginchecker/checker_test.go

@@ -9,7 +9,7 @@ import (
 
 func TestIsPreinstalled(t *testing.T) {
 	cfg := &setting.Cfg{
-		PreinstallPlugins: []setting.InstallPlugin{
+		PreinstallPluginsAsync: []setting.InstallPlugin{
 			{ID: "plugin1"},
 			{ID: "plugin2"},
 		},
@@ -23,7 +23,7 @@ func TestIsPreinstalled(t *testing.T) {
 
 func TestIsPinned(t *testing.T) {
 	cfg := &setting.Cfg{
-		PreinstallPlugins: []setting.InstallPlugin{
+		PreinstallPluginsAsync: []setting.InstallPlugin{
 			{ID: "plugin1", Version: "1.0.0"},
 			{ID: "plugin2"},
 		},