Knauer Valve Driver: Allow use of Valve Unifier 4.1 Command Protocol

# Feature Description

As someone using a Kanuer valve system I want to be able to keep using the newer models, which are ethernet connected and use a different command protocol.

## Explanation
These valve drivers are used to feed different substances through to different places.

### Additional Information
- There is a manual in the usual location
- It should be possible to extend the existing driver to allow an ethernet connection instead, and load an appropriate db with an appropriate protocol file to allow communication without making those doing set up to do anything more than tell it which comms method to use
- The following functions and new commands should be added:
- Report on and set the remote state (`REMOTE?`, `REMOTE`, and `LOCAL` commands)
- Check on the status of the device (`STATUS?` command)
- Set and read the position (`POSITION` command)
- Check for errors and reset the error state (`ERROR?` and `RESET_ERROR` command)
- Note that there are commands available in relation to programs and more, this is not being detailed here as at present these are not used

# Acceptance Criteria
- [ ] The Emulator is extended to have the new commands available
- [ ] The tests are extended to ensure that both the older and newer commands function as expected
- [ ] The comms methods are extended to cover Ethernet as well as RS232
- [ ] The new commands are made available via appropiate protocol and db files when the IOC is built

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