Add missing tabs to org projects page (#22705)

Fixes https://github.com/go-gitea/gitea/issues/22676

Context Data `IsOrganizationMember` and `IsOrganizationOwner` is used to
control the visibility of `people` and `team` tab.

2871ea0809/templates/org/menu.tmpl (L19-L40)

And because of the reuse of user projects page, User Context is changed
to Organization Context. But the value of `IsOrganizationMember` and
`IsOrganizationOwner` are not being given.

I reused func `HandleOrgAssignment` to add them to the ctx, but may have
some unnecessary variables, idk whether it is ok.

I found there is a missing `PageIsViewProjects` at create project page.

routers/web/org/home.go

@@ -156,6 +156,7 @@ func Home(ctx *context.Context) {
 	pager.SetDefaultParams(ctx)
 	pager.AddParam(ctx, "language", "Language")
 	ctx.Data["Page"] = pager
+	ctx.Data["ContextUser"] = ctx.ContextUser
 
 	ctx.HTML(http.StatusOK, tplOrgHome)
 }