feat: Update rules to fit tree-sitters GLR parsing

[bugwelle]

The grammar was originally an LL grammar (I used it as a base for this project, but modified it heavily afterward). But tree-sitter is GLR and some rules can be updated to better "fit" into GLR.

I want to stabilize the tree eventually. This needs to be done step by step. This issue is to keep track of it.

• [x] Namespaces
• [x] Service
• [x] Context
• [x] Names (definition/element names)
• [x] associations (type_association_cont)
• [x] Entities
• [x] Views
• [x] Annotation Definitions
• [x] Annotation Assignments
• [x] Scalar Types
• [x] Structured Types
• [x] Type References
• [x] Aspects
• [x] Events
• [x] Functions
• [x] Actions
• [x] Return Type
• [x] Projections
• [x] Queries (SELECT)
• [x] Expressions
• [x] Conditions
• [x] Extend/Annotate

[bugwelle]

Changes are on branch https://github.com/cap-js-community/tree-sitter-cds/tree/dev