Chore: Update test database initialization (#81673)

* streamline initialization of test databases, support on-disk sqlite test db

* clean up test databases

* introduce testsuite helper

* use testsuite everywhere we use a test db

* update documentation

* improve error handling

* disable entity integration test until we can figure out locking error

pkg/services/pluginsintegration/pluginsettings/service/service_test.go

@@ -12,8 +12,13 @@ import (
 	"github.com/grafana/grafana/pkg/services/secrets"
 	"github.com/grafana/grafana/pkg/services/secrets/fakes"
 	secretsManager "github.com/grafana/grafana/pkg/services/secrets/manager"
+	"github.com/grafana/grafana/pkg/tests/testsuite"
 )
 
+func TestMain(m *testing.M) {
+	testsuite.Run(m)
+}
+
 func TestService_DecryptedValuesCache(t *testing.T) {
 	t.Run("When plugin settings hasn't been updated, encrypted JSON should be fetched from cache", func(t *testing.T) {
 		ctx := context.Background()