Revert "remove unnecessary actor to tighten ADL resolution. the one above it is"

This reverts commit 63045e86113112d0df3867b018a8346eb47689c6.
Partially revert "Fix for fusion pair to make the compiler select the proper copy"

This reverts commit f3fa7a1dc62aa5e7e60d1395b76ec7f08949820c.
Avoid to elect templated move-ctor as a copy-ctor.