Refactor the setting to make unit test easier (#22405)

Some bugs caused by less unit tests in fundamental packages. This PR
refactor `setting` package so that create a unit test will be easier
than before.

- All `LoadFromXXX` files has been splited as two functions, one is
`InitProviderFromXXX` and `LoadCommonSettings`. The first functions will
only include the code to create or new a ini file. The second function
will load common settings.
- It also renames all functions in setting from `newXXXService` to
`loadXXXSetting` or `loadXXXFrom` to make the function name less
confusing.
- Move `XORMLog` to `SQLLog` because it's a better name for that.

Maybe we should finally move these `loadXXXSetting` into the `XXXInit`
function? Any idea?

---------

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: delvh <dev.lh@web.de>

modules/setting/i18n.go

@@ -47,3 +47,20 @@ func defaultI18nNames() (res []string) {
 	}
 	return res
 }
+
+var (
+	// I18n settings
+	Langs []string
+	Names []string
+)
+
+func loadI18nFrom(rootCfg ConfigProvider) {
+	Langs = rootCfg.Section("i18n").Key("LANGS").Strings(",")
+	if len(Langs) == 0 {
+		Langs = defaultI18nLangs()
+	}
+	Names = rootCfg.Section("i18n").Key("NAMES").Strings(",")
+	if len(Names) == 0 {
+		Names = defaultI18nNames()
+	}
+}