add option to encapsulate

[dwickern]

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

Resolves #197

[dwickern]

Will this change interact safely with fastify-autoload's default with the same name?

[Eomm]

We need a test that verifies what the docs say: does it run all the validations?

[dwickern]

Would you say the 1 test is enough? I'd rather avoid repeating the whole test suite

[Eomm]

All the cases that have not been tested have an undetermined state, so the maintainers can't help whoever opens an issue.

In this case, the maintainer should add a test case for it and add it to the repository etc.. in an endless pain loop.

So, we can discuss about the minimal test suite we need, but yes: 1 test is not enough of a HUGE feature like this.

So I think the minimal test suite for this test suite is:

• check that the feature works as expected:
  • are decorators encapsulated?
  • is the fastify version check working?
  • are mandatory decorators checks applied?
  • is the required plugins option working?
• verify how fastify reacts to this configuration (plugin name chaining)

[mcollina]

lgtm

[Eomm]

Could you integrate this 00d2bdd
commit into this PR before landing?

[dwickern]

Thanks @Eomm; I pushed your changes to this branch