Proposal: introduce execution plugins

@nitzmahone mentioned in Should we add ibm z/OS mainframe host info to the Ansible docs? - #5 by nitzmahone that

[…] the Ansible Core team’s long-term goal has always been to shift most (possibly all) technology- and platform-specific code and docs out to collections via exec subsystem plugins.

That sounds pretty similar to what I mean with ‘execution plugins’, not just from the name, but also from the further explanation.