Support executable templates

[nabertrand]

Summary

This adds support for having executable templates as described in #1224.

Additional Context

This PR makes use of a new manage_execute_permissions boolean config setting, which can be set on an individual template or enabled globally in the common config key. The existing code relied on a :global config setting:

pdk/lib/pdk/template/renderer/v1/legacy_template_dir.rb

Line 59 in 4e46ce2

file_config = @config.fetch(:global, {})

But as far as I can tell that key is no longer valid as neither the Symbol class nor the :global symbol are allowed during YAML parsing:

pdk/lib/pdk/template/renderer/v1/legacy_template_dir.rb

Line 94 in 4e46ce2

YAML.safe_load(PDK::Util::Filesystem.read_file(loc), permitted_classes: [], permitted_symbols: [], aliases: true)

I noticed the current config_defaults file contains a common key, so I thought we could reuse that here.

No spec or acceptance tests have been added and no documentation has been updated because I wanted to wait for consensus on this approach before spending time on testing or documentation.

Related Issues (if any)

#1224

Checklist

• 🟢 Spec tests.
• 🟢 Acceptance tests.
• Manually verified.

[nabertrand]

@jordanbreen28 as discussed in Slack, I've added spec tests in #1289. There's also a related documentation update in puppetlabs/pdk-templates#539

[nabertrand]

Closing in favor of #1289