New Line at End Of File for launchSettings.json

**Is your feature request related to a problem? Please describe.**
When checking in code to github, the pull request UI will call out any file that does not have a new line at the end of a file. This new line is a best practice for files in source control.

**Describe the solution you'd like**
When the launchSettings.json file is generated, it is generated with a new line at the end of the file

**Describe alternatives you've considered**
Manual updates to this file often get overwritten, so manually adding the new line is not suitable.

Start by locating the generator for launchSettings.json in the AWS Toolkit for Visual Studio. Ensure generated files end with a newline, then verify the generated launchSettings.json matches the requested formatting.

Written by the indexing model from the issue text.