Merge forwardport of #11458 to 2.3-develop branch

Applied pull request patch https://github.com/magento/magento2/pull/11458.patch (created by @peterjaap) based on commit(s):
  1. 80ed833
  2. 24d6a57
  3. a19eeb2
  4. 846f117

Fixed GitHub Issues in 2.3-develop branch:
  - #2991: Products added to cart with REST API give total prices equal to zero (reported by @degaray)

app/code/Magento/Quote/Model/QuoteManagement.php

@@ -232,6 +232,7 @@ public function createEmptyCart()
         $quote->setShippingAddress($this->quoteAddressFactory->create());
 
         try {
+            $quote->getShippingAddress()->setCollectShippingRates(true);
             $this->quoteRepository->save($quote);
         } catch (\Exception $e) {
             throw new CouldNotSaveException(__('Cannot create quote'));

app/code/Magento/Quote/Test/Unit/Model/QuoteManagementTest.php

@@ -246,11 +246,15 @@ public function testCreateEmptyCartAnonymous()
         $quoteId = 2311;
 
         $quoteMock = $this->createMock(\Magento\Quote\Model\Quote::class);
-
-        $quoteAddress = $this->createMock(\Magento\Quote\Model\Quote\Address::class);
+        $quoteAddress = $this->createPartialMock(
+            \Magento\Quote\Model\Quote\Address::class,
+            ['setCollectShippingRates']
+        );
+        $quoteAddress->expects($this->once())->method('setCollectShippingRates')->with(true);
 
         $quoteMock->expects($this->any())->method('setBillingAddress')->with($quoteAddress)->willReturnSelf();
         $quoteMock->expects($this->any())->method('setShippingAddress')->with($quoteAddress)->willReturnSelf();
+        $quoteMock->expects($this->any())->method('getShippingAddress')->willReturn($quoteAddress);
 
         $this->quoteAddressFactory->expects($this->any())->method('create')->willReturn($quoteAddress);