Cleanup a few clauses in fabric_view_changes

`#changes{}` record and old `complete` format was deprecated 10 years ago [1].

While at it, cleanup un-necessarily long arg per line call formats.

Coincidentally, this also improve code coverage a bit:

```
fabric_view_changes           :  72% (pr)
fabric_view_changes           :  71% (main)
```

[1] https://github.com/apache/couchdb/commit/865b5555771e6099c9b34b1b14d2428ce02e50c3
2 files changed