feat: support column alias in datafusion

[ChunxuTang]

This PR adds the support of column alias through keyword AS in the datafusion planner. After this change, the planner would support queries like MATCH (p:Person) RETURN p.name AS person_name.

[codecov-commenter]

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Additional details and impacted files

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  Coverage        ?   77.24%           
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  Lines           ?     5664           
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  Hits            ?     4375           
  Misses          ?     1289           
  Partials        ?        0           

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rust-unittests	77.24% <100.00%> (?)

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