[C++] Aggregate kernel should not mandate alignment

When using arrow's aggregate kernel with table transferred from arrow flight (DoGet), it may crash at arrow::util::CheckAlignment(). However using original data it works well, also if I first serialize the transferred table into bytes then recreate an arrow table using the bytes, it works well.

"flight-alignment-test" attached is the minimal test that can produce the issue, which basically does "sum(total_revenue) group by l_suppkey" using the table from "DoGet()". ("DummyNode" is just used to be the producer of the aggregate node as the producer is required to create the aggregate node)

**Reporter**: [Yifei Yang](https://issues.apache.org/jira/browse/ARROW-17783)
#### Original Issue Attachments:
- [flight-alignment-test.zip](https://issues.apache.org/jira/secure/attachment/13049529/flight-alignment-test.zip)

_{**Note**: *This issue was originally created as [ARROW-17783](https://issues.apache.org/jira/browse/ARROW-17783). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*}

Start with the attached flight-alignment-test.zip, reproduce the crash with the DoGet-produced table, and trace the aggregate kernel path to arrow::util::CheckAlignment(). Compare it with the original and serialized/recreated tables. Done means the aggregate operation no longer crashes for the transferred table and the minimal reproduction is covered by a regression test.

Written by the indexing model from the issue text.