fix: Gotcha with validation order

[jhurd2326]

Description

Currently there is a gotcha where if you have validations that run before the has_state_machine call in a class definition, it will end up clearing out any existing errors on the object b/c we delegate the errors method to the object of the state instance and valid? clears any existing errors. This PR fixes this issue by removing the delegation and manually adding the errors to the object.

Checklist

• I added the appropriate label to this PR.
• I have made corresponding changes to the documentation if needed.
• I have added tests that prove my change is effective.

Merging

Please choose the type of release that is required for this change.

• 1. Major (breaking change)
• 2. Minor (non-breaking, backwards compatible change)
• 3. Patch (non-breaking, backwards compatible bug fix)
• 4. No immediate release is required

[bharget]

🤘