Add user/organization code search (#19977)

Fixes #19925 

Screenshots:

![attels](https://user-images.githubusercontent.com/165205/173864718-fe789429-55bc-4cad-808c-9f02f335cddf.png)

modules/context/org.go

@@ -130,6 +130,7 @@ func HandleOrgAssignment(ctx *Context, args ...bool) {
 	ctx.Data["IsOrganizationOwner"] = ctx.Org.IsOwner
 	ctx.Data["IsOrganizationMember"] = ctx.Org.IsMember
 	ctx.Data["IsPackageEnabled"] = setting.Packages.Enabled
+	ctx.Data["IsRepoIndexerEnabled"] = setting.Indexer.RepoIndexerEnabled
 	ctx.Data["IsPublicMember"] = func(uid int64) bool {
 		is, _ := organization.IsPublicMembership(ctx.Org.Organization.ID, uid)
 		return is