Fix derivation of LocalExchange single stream property

[sopel39]

Description

LocalExchange will preserve single stream property only if:

1. global partitioning is either on coordinator or single-node
2. LocalExchange is gathering

Release notes

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# General
* Fix a correctness bug for queries with certain complex window operators used in sequence 

[martint]

This still produces an incorrect plan:

 Fragment 0 [SINGLE]
     Output layout: [orderkey, count]
     Output partitioning: SINGLE []
     Output[columnNames = [orderkey, _col1]]
     │   Layout: [orderkey:bigint, count:bigint]
     │   Estimates: {rows: ? (?), cpu: 0, memory: 0B, network: 0B}
     │   _col1 := count
     └─ TopN[count = 5, orderBy = [orderkey ASC NULLS LAST]]
        │   Layout: [orderkey:bigint, count:bigint]
        └─ LocalExchange[partitioning = SINGLE]
           │   Layout: [orderkey:bigint, count:bigint]
           │   Estimates: {rows: 5 (90B), cpu: 0, memory: 0B, network: 0B}
           └─ LimitPartial[count = 5, inputPreSortedBy = [orderkey]]           <<<<< input to this limit is not pre-sorted by orderkey
              │   Layout: [orderkey:bigint, count:bigint]
              │   Estimates: {rows: 5 (90B), cpu: 90, memory: 0B, network: 0B}
              └─ LocalExchange[partitioning = ROUND_ROBIN]
                 │   Layout: [orderkey:bigint, count:bigint]
                 │   Estimates: {rows: ? (?), cpu: ?, memory: 0B, network: 0B}
                 └─ Window[orderBy = [orderkey ASC NULLS LAST]]
                    │   Layout: [orderkey:bigint, count:bigint]
                    │   count := count() RANGE UNBOUNDED_PRECEDING CURRENT_ROW
                    └─ LocalExchange[partitioning = SINGLE]
                       │   Layout: [orderkey:bigint]
                       │   Estimates: {rows: 15000 (131.84kB), cpu: 0, memory: 0B, network: 0B}
                       └─ RemoteSource[sourceFragmentIds = [1]]
                              Layout: [orderkey:bigint]

[martint]

Actually, disregard. It's correct -- it's sorted at the stream level.