Fix crash on the automated visibility keyword

[adityaanikam]

Fixes #471

The grammar accepts an automated visibility section and builds a VisibilityNode for it, but VisibilityNodeImpl.getVisibility had no case for that token type and threw AssertionError: Visibility node has unexpected token type: AUTOMATED. That aborted the scan of any file with an automated section.

This adds an AUTOMATED value to VisibilityType, as suggested in review. Treating it as PUBLIC was wrong because ConsecutiveVisibilitySectionCheck compares visibilities by identity, so a public section followed by an automated one was reported as consecutive.

What follows from the new value:

• Visibility::isAutomated is new, and Visibility::isPublic also returns true for automated members, in the same way isPublished includes implicit published and isProtected includes strict protected. Without that, NameResolver would treat automated methods as inaccessible and the unused-code checks would stop treating them as API.
• VisibilitySectionOrderCheck keeps its order in a map keyed by every VisibilityType, so it needed an entry. I gave automated the same rank as public, so the two can appear in either order without an issue, and published still has to come last. I can rank it differently if you prefer.
• A generic constructor constraint is satisfied by a default constructor declared in an automated section, as it is for public.
• CHANGELOG.md lists the new API members and the isPublic change.

Testing: VisibilityNodeImplTest covers the visibility of every keyword plus isPublic and isAutomated. ConsecutiveVisibilitySectionCheckTest has the public then automated case from the review, which fails on the previous mapping with a false issue, and consecutive automated sections. VisibilitySectionOrderCheckTest and ConstructorConstraintTest have automated cases. All of these pass, and I ran mvn install for delphi-frontend and delphi-checks, including the format and license checks.

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