[Rust] [DataFusion] Predicate Pushdown Improvement: treat predicates separated by AND separately

[asfimport]

As discussed by @jorgecarleitao and @houqp here: #7880 (review)

If a predicate is a conjunction (aka AND'd) together, each of the clauses can be treated separately (e.g. a single filter expression A > 5 And B < 4 can be broken up and each of A > 5 and B < 4 can be potentially pushed down different levels

The filter pushdown logic works for the following case (when a and b are are separate selections, predicate for a is pushed below the Aggregate in the optimized plan):

********Original plan:
Selection: #b GtEq Int64(1)
  Selection: #a LtEq Int64(1)
    Aggregate: groupBy=[[#a]], aggr=[[MIN(#b)]]
      TableScan: test projection=None

********Optimized plan:
Selection: #b GtEq Int64(1)
  Aggregate: groupBy=[[#a]], aggr=[[MIN(#b)]]
    Selection: #a LtEq Int64(1)
      TableScan: test projection=None

But not for this when a and b are AND'd together

********Original plan:
Selection: #a LtEq Int64(1) And #b GtEq Int64(1)
  Aggregate: groupBy=[[#a]], aggr=[[MIN(#b)]]
    TableScan: test projection=None
********Optimized plan:
Selection: #a LtEq Int64(1) And #b GtEq Int64(1)
  Aggregate: groupBy=[[#a]], aggr=[[MIN(#b)]]
    TableScan: test projection=None

Reporter: Andrew Lamb / @alamb
Assignee: Jorge Leitão / @jorgecarleitao

PRs and other links:

• GitHub Pull Request #8903

_{Note: This issue was originally created as ARROW-9771. Please see the migration documentation for further details.}

[asfimport]

Andrew Lamb / @alamb:
Issue resolved by pull request 8903
#8903