* changed collection arg to argregate on 2.4 network modules
* replace users with aggregate in eos_user, junos_user, nxos_user
* added version_added to places where we replaced users with aggregate in the docs
* fix ios_static_route test
* update tests to reference aggregate instead of collection/users
* junos_linkagg implementation and junos modules refactor
* junos_linkagg implementation
* junos_linkagg integration test
* net_linkagg integration test for junos
* decouple `load_config` and `commit` operations,
to allow single commit (in case on confirm commit) and
to perform batch commit (multiple `load_config` followed by single
`commit`)
* Other related refactor
* Fix CI issues
* Fix unit test failure
