IDL41 — Clarify and perhaps expand where annotations can be applied

The specification should allow application of annotations to:
declarations, members, function parameters, union discriminator, enumerator literals, typedefs, sequence parameter, array parameter.

Some examples:

struct SS {
    @MemberAnnotation(value)  MyType  m1;
};

emum EE {
    @Value(value)  Enum1;
};

union MyUnion switch ( @key long ) {
   case 1:
       @CaseMemberAnn MT1 m1;
   defalt:
       long l;
};
struct SS {
    @shared sequence< MyType, 3>   m1;
    sequence<@shared  MyType, 3>   m1;

    @shared MyType m1[3];
    MyType @shared m1[3];

    @shared MyMatrix mm[3][4];
    MyMatrix @shared mm[3][4];
};


typedef MyType @shared MyTypeArray3[3];
typedef @shared MyType MyTypeArray3[3];

Clarify application rules for annotations

An annotation can be placed on any IDL constructs or sub-constructs.
Stating that in the grammar rules complicates dramatically all the rules and creates a dependency issue between building-blocks.
The proposed solution is therefore:

1. to remove from the grammar any reference towards where annotations can be placed – cf. rule (202), as it wrongly gave the impression that annotations could only be placed on first-level definitions.
2. to state more clearly in the text that annotations can be placed on any IDL constructs and sub-constructs.

(Note that the format for applying annotation remains defined by EBNF rules as it was).