measuring unique relays.
Create new module heartbeat.

Closes: #28652

because the http server is not concurrent/asynchronous and there
are as many processes as tox environments querying the http server.

It was forgotten in #28566

Closes: #28567

and priority list counters

Part of #28567.

Part of #28567.

Part of #28567.

about the number of times it was in a priority list.
Part of #28567.

Part of #28567.

and the number of times the relay was in a priority list.
Part of #28567.

and number of times in a priority list attrs and methods,
to be able to store the data.
Part of #28567.

in the results file.

Part of #28567.

when mesuring the relay.

Part of #28567.

to store all the possible errors while measuring a relay.

It adds more technical debt, since there should be only
a ResultError class.

Part of #28567.

Since all the other bandwidth values are in bytes and sbws should
work with bytes until it generates the final `bw`.

Closes: #29707. Bugfix v1.0.3.

used in the bandwidth file, so that it is less confusing and less
prone to errors.

The total number of consensuses seen in the last days.

Part of #28566.

Include a KeyValue in each bandwidth line with the number of
times the relay has been in a consensus in the past days.

Part of #28566.

to the state file.
To know the total number of consensus seen in the last days.

Part of #28566.

for every result that is stored.

Part of #28566.

Part of #28566.

that have been seen for a relay and for the relay list.

Part of #28566.

for each relay and for the list of relays when fetching new
network statuses.
To count the number of times a relay was in a consensus and how
many consensuses have been seen.
In the test network router status entries don't have document
attribute.
Part of #28566

The pool can queue all the relays to be measured,
but this inner loop was not adding more worker threads to the pool
unit it finishs the current threads.
Instead, wait for all the worker threads in the pool to finish
or try to get the status after waiting enough.

Closes: #28864, #28865. Bugfix v1.0.0

that are not measured or not reported in the bandwidth file.

Part of #29591.

Part of #29591.

when creating a Bandwidth Line from results

Part of #29591.

(maybe the number is right this time?)

because there was a commit missing between `1.0.3` and `1.0.4-dev0`
and what is released as `1.0.3` has version `1.0.4-dev0` and it
can not be fixed now.

When SocketClosed is raised and the scanner is stopping, catch the
exception.
In #28869 similar exceptions were catched, but this was forgotten.

Bugfix v0.6.0.