Add a capacity testcase to test the type system limits with large number of methods

[VSadov]

Add a testcase under src/tests/async/capacity with 3 scenarios:

• allocate an instance of a class with 40000 methods that return int. The allocation should succeed.
• allocate an instance of a class with 32750 methods that return Task. The allocation should succeed.
• make a call to a method that allocates an instance of a class with 32763 methods that return Task. The call should throw an exception.

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