Allow live configuration of dynamic settings in Neo4j

[moxious]

Some settings in Neo4j can be dynamically managed:

https://neo4j.com/docs/operations-manual/current/configuration/dynamic-settings/

Neo4jConfiguration should allow for changing these.

[moxious]

This is kind of blocked by lack of a good design idea so far. Probably we wouldn't do this on the configuration tab, because the dynamic conf settings are applicable to vastly different areas of the system. So rather it might be done as a way of changing other features in their appropriate place.

Secondly -- need to be careful with this because most of halin is read-only, and it needs to be made clear that in this case, halin would change the system, more of a management rather than diagnostic tool. Of course there's already precedent for that (user management)