Improve {Set,Map}.fromAscList and friends

Following up on https://github.com/haskell/containers/issues/949#issuecomment-1574528332

This PR is based off #962, so marking as draft.

This PR improves

Set.fromAscList, Set.fromDescList
Map.fromAscList, Map.fromDescList, Map.fromAscListWith, Map.fromDescListWith, Map.fromAscListWithKey, Map.fromDescListWithKey

by making the combine function they use a good consumer and producer in terms of fusion. This gets rid of the intermediate list always created today, and also fuses with the input list if possible.

Benchmarks on GHC 9.2.5:

Before

``` Set fromAscList: OK (0.20s) 50.1 μs ± 2.9 μs, 240 KB allocated, 2.4 KB copied, 8.0 MB peak memory fromAscList:fusion: OK (0.19s) 89.5 μs ± 5.7 μs, 528 KB allocated, 6.8 KB copied, 8.0 MB peak memory fromDescList: OK (0.22s) 51.2 μs ± 2.9 μs, 240 KB allocated, 2.4 KB copied, 8.0 MB peak memory fromDescList:fusion: OK (0.18s) 88.9 μs ± 5.7 μs, 559 KB allocated, 7.3 KB copied, 8.0 MB peak memory Map fromAscList: OK (0.18s) 41.9 μs ± 3.6 μs, 343 KB allocated, 5.2 KB copied, 10 MB peak memory fromAscList:fusion: OK (0.13s) 63.0 μs ± 6.0 μs, 792 KB allocated, 15 KB copied, 10 MB peak memory fromDescList: OK (0.17s) 40.5 μs ± 3.9 μs, 343 KB allocated, 5.5 KB copied, 10 MB peak memory fromDescList:fusion: OK (0.25s) 63.1 μs ± 5.3 μs, 824 KB allocated, 16 KB copied, 10 MB peak memory ```

After

Set
  fromAscList:         OK (0.18s)
    21.3 μs ± 1.4 μs, 128 KB allocated, 1.4 KB copied, 8.0 MB peak memory, 57% less than baseline
  fromAscList:fusion:  OK (0.89s)
    13.3 μs ± 221 ns, 144 KB allocated, 1.9 KB copied, 8.0 MB peak memory, 85% less than baseline
  fromDescList:        OK (0.18s)
    20.9 μs ± 1.6 μs, 128 KB allocated, 1.5 KB copied, 8.0 MB peak memory, 59% less than baseline
  fromDescList:fusion: OK (0.23s)
    13.7 μs ± 737 ns, 144 KB allocated, 2.0 KB copied, 8.0 MB peak memory, 84% less than baseline

Map
  fromAscList:        OK (0.22s)
    25.5 μs ± 2.0 μs, 152 KB allocated, 2.1 KB copied,  10 MB peak memory, 39% less than baseline
  fromAscList:fusion: OK (0.30s)
    18.0 μs ± 677 ns, 232 KB allocated, 4.3 KB copied,  10 MB peak memory, 71% less than baseline
  fromDescList:        OK (0.21s)
    25.1 μs ± 1.4 μs, 152 KB allocated, 2.1 KB copied,  10 MB peak memory, 38% less than baseline
  fromDescList:fusion: OK (0.20s)
    50.2 μs ± 3.1 μs, 577 KB allocated,  11 KB copied,  10 MB peak memory, 20% less than baseline

Some observations:

There is no allocations penalty (unlike #950), likely because we rid of the intermediate list and avoid a lot of allocations there.
Map's fromDescList:fusion improves but not as much as fromAscList:fusion. The cause seems be that fusion with [n,n-1..1] does not work out as well as [1..n], but I don't know why and didn't dig into it much.

haskell / containers

Improve {Set,Map}.fromAscList and friends #963