Rollup merge of #143685 - LorrensP-2158466:merge-import-bindings, r=petrochenkov

Resolve: merge `source_bindings` and `target_bindings` into `bindings`

Attempts to merge the 2 fields `source_bindings` and `target_bindings` of `ImportKind::Single` into 1 field called `bindings`.

r? ````@petrochenkov````

Author: matthiaskrgr