add function to check if file/dir exists

[eveld]

• fix data_with_permissions
• fix exec output correctly being set from local exec
• change path to put local install so it works on macos (not sure why this changed, but getting permission denied otherwise)
• removed functions that no longer exist from functions example

This depends on jumppad-labs/hclconfig#28 so the dependency version of hclconfig will need to be updated before merging