feat: add Very Good Security plugin

[dmarynych]

Hello Netlify team 🙌
This is the first version of the Very Good Security plugin. It lets you update VGS routes at the same time as your site deployments. Without this plugin, you would need to manually update VGS routes via UI/CLI or set up a separate CI pipeline.

Are you adding a plugin or updating one?

• Adding a plugin
• Updating a plugin

Have you completed the following?

• Read and followed the plugin author guidelines.
• Included all required fields in your entry.
• Tested the plugin locally and on Netlify, using the plugin version stated in your entry.

Test plan
To test the plugin, please follow README in the repo or try example project

[ascorbic]

Hey! This looks great. Thanks for the contribution. Just wanted to check that the API URL is correct. In your config.json it has the sandbox URL. Is that expected?