intellisense for datalogging should not suggest columns already used in a log call

[jaustin]

Describe the bug

When you're logging columns, it would be good for Intellisense not to suggest columns already used in that log statement.

If you call something like:
datalogger.log(datalogger.createCV("compost", 1), datalogger.createCV("compost", 2), datalogger.createCV("compost", 3))
You will only get a single row with '3' as the entry for 'compost'

To Reproduce

Expected behavior

I think the already used values should be removed from intellisense.

[jaustin]

CC @carlosperate @JohnVidler

[abchatra]

@riknoll can we do this if the one column is already used in the same block, skip suggesting it.