[28.x backport] cli-plugins/manager: various fixes and deprecations#6269

thaJeztah merged 8 commits intodocker:28.xdocker/cli:28.xfrom

thaJeztah:28.x_backport_plugin_manager_unexportthaJeztah/cli:28.x_backport_plugin_manager_unexportCopy head branch name to clipboard