Implement non-interactive mode

This is for node maintenance (cluster expansion, node replacement) so that we can bring a node up and not worry about it participating in views. I've only done light testing but I wanted to start a discussion before I go too far down this rabbit hole.

Everything appears to work. There's a few commits for silencing some errors. And a slightly unrelated mem3 bug fix. Will tag with other PRs as well.

BugzId: 18955