Also enable the warning for T_DATA allocator.

Must not be a bad idea to improve documents. [ci skip]

Truly editorial fix for comments.  This works better with Emacs'
set-justification-full function. [ci skip]

Previous code failed to compile on MSVC. Log:
https://github.com/ruby/ruby/pull/4371/checks?check_run_id=2304484466

This is possibly due to the fact that:

1. `Data_Wrap_Struct(...)` appears in a source code
2. which expands to `rb_data_object_wrap(...)`
3. which expands to `RUBY_MACRO_SELECT(rb_data_object_wrap_, RUBY_UNTYPED_DATA_WARNING)`
4. which expands to `rb_data_object_wrap_0`
5. which expands to `rb_data_object_wrap`, so far so good, but
6. this is a recursive macro expansion (see step 2).  Everybody stops expanding...
    - in step 4 for MSVC, and
    - in step 5 for GCC etc.

I have no idea why but this proposed changeset prevents MSVC from
stopping at step 4.

Use of TOKEN_PASTE was a bad idea at the first place.  Just use ##
everywhere.  Nobody practically lacks token pasting.

* Use the wrapper of rb_cObject instead of data access
* Replaced rest of extentions
* Updated the version guard for Data
* Added the version guard of rb_cData

To fix build failures.

Devs do not love "impl".