Introduce AliasedRelation in logical plan

[andygrove]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.
If I have a SQL query such as SELECT * FROM person AS peeps there is no way to extract the original table name person from the logical plan. It looks like the alias name is pushed down to the TableScan node and the original name is discarded.

Describe the solution you'd like

I would like to include an AliasedRelation node to better represent the query.

For example:

Projection(*)
  AliasedRelation(name="peeps")
    TableScan(name="person")

This would not change the physical plan.

Describe alternatives you've considered
None

Additional context
None

[andygrove]

Fixed in #2172