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

routers/api/v1/org/member.go

@@ -18,11 +18,12 @@ import (
 )
 
 // listMembers list an organization's members
-func listMembers(ctx *context.APIContext, publicOnly bool) {
+func listMembers(ctx *context.APIContext, isMember bool) {
 	opts := &organization.FindOrgMembersOpts{
-		OrgID:       ctx.Org.Organization.ID,
-		PublicOnly:  publicOnly,
-		ListOptions: utils.GetListOptions(ctx),
+		Doer:         ctx.Doer,
+		IsDoerMember: isMember,
+		OrgID:        ctx.Org.Organization.ID,
+		ListOptions:  utils.GetListOptions(ctx),
 	}
 
 	count, err := organization.CountOrgMembers(ctx, opts)
@@ -73,16 +74,19 @@ func ListMembers(ctx *context.APIContext) {
 	//   "404":
 	//     "$ref": "#/responses/notFound"
 
-	publicOnly := true
+	var (
+		isMember bool
+		err      error
+	)
+
 	if ctx.Doer != nil {
-		isMember, err := ctx.Org.Organization.IsOrgMember(ctx, ctx.Doer.ID)
+		isMember, err = ctx.Org.Organization.IsOrgMember(ctx, ctx.Doer.ID)
 		if err != nil {
 			ctx.Error(http.StatusInternalServerError, "IsOrgMember", err)
 			return
 		}
-		publicOnly = !isMember && !ctx.Doer.IsAdmin
 	}
-	listMembers(ctx, publicOnly)
+	listMembers(ctx, isMember)
 }
 
 // ListPublicMembers list an organization's public members
@@ -112,7 +116,7 @@ func ListPublicMembers(ctx *context.APIContext) {
 	//   "404":
 	//     "$ref": "#/responses/notFound"
 
-	listMembers(ctx, true)
+	listMembers(ctx, false)
 }
 
 // IsMember check if a user is a member of an organization