Refactor locale&string&template related code (#29165)

Clarify when "string" should be used (and be escaped), and when
"template.HTML" should be used (no need to escape)

And help PRs like  #29059 , to render the error messages correctly.

models/actions/runner.go

@@ -97,7 +97,7 @@ func (r *ActionRunner) StatusName() string {
 }
 
 func (r *ActionRunner) StatusLocaleName(lang translation.Locale) string {
-	return lang.Tr("actions.runners.status." + r.StatusName())
+	return lang.TrString("actions.runners.status." + r.StatusName())
 }
 
 func (r *ActionRunner) IsOnline() bool {

models/actions/status.go

@@ -41,7 +41,7 @@ func (s Status) String() string {
 
 // LocaleString returns the locale string name of the Status
 func (s Status) LocaleString(lang translation.Locale) string {
-	return lang.Tr("actions.status." + s.String())
+	return lang.TrString("actions.status." + s.String())
 }
 
 // IsDone returns whether the Status is final