MM-11262: database config store (#10281)

* vendor github.com/jmoiron/sqlx

* MM-11262: introduce a database store

* revert unnecessary fmt.Errorf

* simplify unit test helper methods

* remote TODO re: retry

* relocate initializeConfigurationsTable for clarity

* factor out a commonStore

* acquire database config lock on close for safety

* add missing header

* fix lock comment

app/helper_test.go

@@ -51,7 +51,7 @@ func setupTestHelper(enterprise bool, tb testing.TB) *TestHelper {
 		panic(err)
 	}
 
-	options := []Option{ConfigFile(tempConfig.Name(), false)}
+	options := []Option{Config(tempConfig.Name(), false)}
 	options = append(options, StoreOverride(mainHelper.Store))
 	options = append(options, SetLogger(mlog.NewTestingLogger(tb)))