Merge setting.InitXXX into one function with options (#24389)

This PR will merge 3 Init functions on setting packages as 1 and
introduce an options struct.

cmd/main_test.go

@@ -7,14 +7,8 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models/unittest"
-	"code.gitea.io/gitea/modules/setting"
 )
 
-func init() {
-	setting.SetCustomPathAndConf("", "", "")
-	setting.InitProviderAndLoadCommonSettingsForTest()
-}
-
 func TestMain(m *testing.M) {
 	unittest.MainTest(m, &unittest.TestOptions{
 		GiteaRootPath: "..",