Reduced the length of the cloned app template folder name

[lucashuy]

Why is this change necessary?

This is one of the changes being made to help reduce the overall length of cloned app templates to avoid reaching the maximum path length in Windows.

How does it address the issue?

Changes the folder name from aws-sam-cli-app-templates to tmpl for Windows machines.

What side effects does this change have?

Existing Windows installations with an aws-sam-cli-app-templates folder in their %appdata%/AWS SAM directory will have that folder remain there until it is manually deleted.

Mandatory Checklist

PRs will only be reviewed after checklist is complete

• Add input/output type hints to new functions/methods
• Write design document if needed (Do I need to write a design document?)
• Write/update unit tests
• Write/update integration tests
• Write/update functional tests if needed
• make pr passes
• make update-reproducible-reqs if dependencies were changed
• Write documentation

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[hawflau]

Approved with question - With this change, does that mean we can/should revert PR #3950?

[lucashuy]

Approved with question - With this change, does that mean we can/should revert PR #3950?

From what I can gather, we can just leave that PR fix in place since its not changing anything about the way we digest the templates. Even though we could remove it since we are now reducing the paths of our templates, imo it doesn't hurt to leave it in so that we know that this won't happen with git in the future.