Handle "fractionalSecondsPrecision" in VSCJ

[redcatbear]

Situation

We want to be able to control the precision of the timestamp more fine grained. The VS "create schema" requests with get a new parameter fractionalSecondsPrecision which the VS needs to respect.

Acceptance Criteria

Beta Give feedback

1. In VS requests the optional parameter fractionalSecondsPrecision is read and the timestamp type configured accordingly
2. If the parameter is missing, the precision defaults to 3
3. In responses the the optional parameter is always set.
4. A test against 7.1 proves that the extra parameter is ignored (i.e. does not break the interface)
5. User documentation updated
6. Developer documentation updated