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ARROW-12683: [C++] Enable fine-grained I/O (coalescing) in IPC reader

This PR tries to fix https://issues.apache.org/jira/browse/ARROW-12683 ([C++] Enable fine-grained I/O (coalescing) in IPC reader)

This is my first PR for arrow, please forgive my ignorance and let me know the issues for code format/convention/etc.
And probably I chose a wrong issue as the first problem I want to contribute since after investigating this issue for a while, I realize it is more difficult than I expected :(

Currently I chose an approach that can re-use the current code as much as possible in `ArrayLoader`, to do that, I use a no-op random access file to record the IO and replay only the necessary read operation later. But I am not certain if this is the best approach for solving this issue, and if this kind of approach doesn't fit, feel free to reject this PR, and please let me know how this should be done and I can give it another try.

Besides passing the unit tests, I verified the IO behavior under Linux manually by watching the file pages loaded in page cache, and it works largely as I expected, and the IO saving varies depending on the specific field to be accessed.

Closes #11486 from niyue/feature/fine_grained_io

Authored-by: Yue <niyue.com@gmail.com>
Signed-off-by: David Li <li.davidm96@gmail.com>