Improve unit test cases for annotation with readonly types

[KRVPerera]

Description:

• add readonly type test cases
  There are already usages for read-only values
  refer comment: Restrict annotation value to true, map<anydata|readonly> , map<anydata|readonly>[] #23473 (review)
  Object read-only check for annotations is skipped for now. This issue is created to add unit test cases for other scenarios.

• We can do regex expression check for unit test cases from ballerina side as well.
  Restrict annotation value to true, map<anydata|readonly> , map<anydata|readonly>[] #23473 (comment)

• Fix PR suggestion:
  Restrict annotation value to true, map<anydata|readonly> , map<anydata|readonly>[] #23473 (comment)

• Add a test case to reflect runtime changes.
  We have override copy, freezeDirect like methods to allow Abstract objects for cloneReadOnly.

type Annot record {|
   service s;
   object {} t;
   handle u;
   typedesc v;
   function () w;
|};

Related Issues (optional):
#24217 (objects are skipped for now)
#24246 (enable readonly object checks for annotation value)

Suggested Labels (optional):
Area/Language

Suggested Assignees (optional):
KRV/Perera