download was being inferred. It's now being set on each and will raise
an error if node is provided. Also removed a duplication on params
variable.

Stream production wasn't pausing or stopping as asked by protocol.

Was too high due a left over from some bug hunting. 20 is enough to
check both zero sized and under/equal/above tag size.

As it's blocking and Twisted already stored everything on a file.

-- Related: #8809

-- Resolves: #8809

-- Related: #8809

-- Resolves #8773

When it's the first time a test is run, there'll not be previous results
to compare against. The script that calculates outliers was not prepared
for this situation. This commit just fixes that.

Closes: 9016