Add no internal linter for examples

[RodrigoVillar]

This PR revolves #1572 by adding a simple linter at checks for the use of internal packages within examples/

If the linter passes, it returns the following:

Ok.

If there is an instance of internal being used, it returns a similar message as seen below for each violation and exits with code 1:

Violation: /Users/rodrigo.villar/go/src/github.com/ava-labs/hypersdk/examples/morpheusvm/actions/transfer.go imports from /internal

This PR also adds the internal linter as part of the CI tests for HyperSDK

[aaronbuchwald]

Would it be possible to look into why depguard is not giving us what we want here?