Deploy Workflow quits unexpectedly when SAM Template has no Functions

**Describe the bug**
Deploying a SAM App that contains no Function resources causes an Error to be thrown which interrupts the Deploy process.

**To Reproduce**
1. Create a new SAM App
2. Edit the template.yaml file
a. Delete all Function resources
b. Add a different resource, like a DynamoDB Table
3. Deploy the app. The deploy workflow will stop, and an error is logged. User is not given feedback.

**Expected behavior**
The SAM App is deployed, creating a CloudFormation stack.

**Desktop (please complete the following information):**
- OS: N/A
- Visual Studio Code Version: N/A
- AWS Toolkit for Visual Studio Code Version: 1.0.0

Start by reproducing the deploy workflow with a template.yaml containing a DynamoDB Table but no Function resources, as described in the issue. Done means the workflow does not throw or stop unexpectedly, provides appropriate feedback, and deploys the app by creating the expected CloudFormation stack.

Written by the indexing model from the issue text.