Enhance AST and rendering for annotations, enums, and requirements

[Malcolmnixon]

This pull request delivers the "Annotating elements & compartment depth" feature for the SysML2 tools, improving both the semantic model and the General View layout to support documentation notes, enumeration literal values, and deeper compartment rendering for requirements, concerns, and constraints. It also updates the documentation and gallery model to demonstrate these capabilities. The most important changes are grouped below:

Semantic Model & AST Builder Enhancements:

• The AstBuilder now captures all relevant content for compartment depth: enumeration values (with a new VisitEnumeratedValue and CollectEnumerationBodyChildren), requirement/concern subject, actor, stakeholder, and constraint members (with new visitors and helpers), and standalone constraint usages/definitions. It also adds a safeguard to prevent nested verify/frame bodies from being incorrectly hoisted. [1] [2] [3] [4]
• The SysmlFeatureNode type gains an ExpressionText field to capture raw constraint expressions, which is used for rendering constraint-kind features.

General View Layout & Rendering:

• GeneralViewLayoutStrategy is updated to thread through definition annotations, enabling the rendering of BoxShape.Note nodes (folded-corner notes) attached to annotated elements, with concatenated annotation text. The layout also pluralizes certain compartment titles using guillemets for stereotype-style headings and renders constraint expressions as raw text. [1] [2] [3] [4]

Documentation & Gallery Model Updates:

• The gallery model (01-drone-general.sysml) is extended with annotated elements, an enum def with values, and a requirement with subject and constraint body to demonstrate the new features. The gallery README is updated to describe these additions.
• Design documentation is updated to describe the new AST builder behaviors, feature node shape, and layout strategy logic. [1] [2] [3] [4] [5] [6] [7] [8]

Scope and Limitations:

• This delivery captures only raw constraint text (not full expression trees) and intentionally does not model nested doc annotations within constraint bodies or support views other than General View. [1] [2]

Summary of Most Important Changes:

• Semantic model and AST builder now fully support documentation notes, enumeration values, and deep compartment content for requirements/concerns/constraints, including new visitors and helpers. [1] [2] [3] [4]
• SysmlFeatureNode gains ExpressionText for constraint-kind features, enabling raw expression rendering.
• General View layout strategy renders annotation notes, stereotype-titled compartments, and constraint expressions as raw text, with updated compartment grouping and formatting logic. [1] [2] [3] [4]
• Documentation and gallery model are updated to demonstrate and explain the new features and rendering behaviors. (Fc08c939cL44R44)
• Scope boundaries are documented: only raw text is captured for constraints, and nested doc inside constraint bodies is intentionally omitted. [1] [2]