Fix package access for admins and inactive users (#21580)

I noticed an admin is not allowed to upload packages for other users
because `ctx.IsSigned` was not set.
I added a check for `user.IsActive` and `user.ProhibitLogin` too because
both was not checked. Tests enforce this now.

Co-authored-by: Lauris BH <lauris@nix.lv>

routers/api/packages/api.go

@@ -58,6 +58,7 @@ func Routes(ctx gocontext.Context) *web.Route {
 	authGroup := auth.NewGroup(authMethods...)
 	r.Use(func(ctx *context.Context) {
 		ctx.Doer = authGroup.Verify(ctx.Req, ctx.Resp, ctx, ctx.Session)
+		ctx.IsSigned = ctx.Doer != nil
 	})
 
 	r.Group("/{username}", func() {
@@ -316,6 +317,7 @@ func ContainerRoutes(ctx gocontext.Context) *web.Route {
 	authGroup := auth.NewGroup(authMethods...)
 	r.Use(func(ctx *context.Context) {
 		ctx.Doer = authGroup.Verify(ctx.Req, ctx.Resp, ctx, ctx.Session)
+		ctx.IsSigned = ctx.Doer != nil
 	})
 
 	r.Get("", container.ReqContainerAccess, container.DetermineSupport)