[FhirResourceTree] Support of elementsDefinition cardinality

[BPierrick]

Problem

There is no support of cardinality for elementDefinitions.

Description

Enhance support. of cardinality for elementDefinitions :

• Completely hide definitions for node that have a max cardinality of 0
• Allow slices node addition when their number is less that their max cardinality
  • Define a UX for this behavior
• Prevent slice/array items creations when their numbers are more/equals to the max cardinality of their parent node max cardinality