Calculate PublicOnly for org membership only once (#32234)

Refactoring of #32211

this move the PublicOnly() filter calcuation next to the DB querys and
let it be decided by the Doer

---
*Sponsored by Kithara Software GmbH*

(cherry picked from commit 43c252dfeaf9ab03c4db3e7ac5169bc0d69901ac)

Conflicts:
	models/organization/org_test.go
	models/organization/org_user_test.go
	routers/web/org/home.go

  rather simple conflict resolution but not trivial
  tests/integration/user_count_test.go had to be adapted (simple)
  because it does not exist in Gitea and uses the modified model

services/context/org.go

@@ -26,7 +26,6 @@ type Organization struct {
 	Organization     *organization.Organization
 	OrgLink          string
 	CanCreateOrgRepo bool
-	PublicMemberOnly bool // Only display public members
 
 	Team  *organization.Team
 	Teams []*organization.Team
@@ -176,10 +175,10 @@ func HandleOrgAssignment(ctx *Context, args ...bool) {
 	ctx.Data["OrgLink"] = ctx.Org.OrgLink
 
 	// Member
-	ctx.Org.PublicMemberOnly = ctx.Doer == nil || !ctx.Org.IsMember && !ctx.Doer.IsAdmin
 	opts := &organization.FindOrgMembersOpts{
-		OrgID:      org.ID,
-		PublicOnly: ctx.Org.PublicMemberOnly,
+		Doer:         ctx.Doer,
+		OrgID:        org.ID,
+		IsDoerMember: ctx.Org.IsMember,
 	}
 	ctx.Data["NumMembers"], err = organization.CountOrgMembers(ctx, opts)
 	if err != nil {