Include skipped builds in database and web ui

We have had an on-and-off relationship with skipped builds in the
database.  Generally we have attempted to exclude them from the db,
but we have occasionally (accidentally?) included them.  The status
quo is that builds with a result of SKIPPED (as well as several
other results which don't come from the executor) are not recorded
in the database.

With a greater interest in being able to determine which jobs ran
or did not run for a change after the fact, this job deliberately
adds all builds (whether they touch an executor or not, whether
real or not) to the database.  This means than anything that could
potentially show up on the status page or in a code-review report
will be in the database, and can therefore be seen in the web UI.

It is still the case that we are not actually interested in seeing
a page full of SKIPPED builds when we visit the "Builds" tab in
the web ui (which is the principal reason we have not included them
in the database so far).  To address this, we set the default query
in the builds tab to exclude skipped builds (it is easy to add other
types of builds to exclude in the future if we wish).  If a user
then specifies a query filter to *include* specific results, we drop
the exclusion from the query string.  This allows for the expected
behavior of not showing SKIPPED by default, then as specific results
are added to the filter, we show only those, and if the user selects
that they want to see SKIPPED, they will then be included.

On the buildset page, we add a switch similar to the current "show
retried jobs" switch that selects whether skipped builds in a buildset
should be displayed (again, it hides them by default).

Change-Id: I1835965101299bc7a95c952e99f6b0b095def085

zuul/manager/__init__.py

@@ -1965,13 +1965,7 @@ class PipelineManager(metaclass=ABCMeta):
             build_set.jobNodeRequestComplete(request.job_name, nodeset)
         # Put a fake build through the cycle to clean it up.
         if not request.fulfilled:
-            fakebuild = build_set.item.setNodeRequestFailure(job)
-            try:
-                self.sql.reportBuildEnd(
-                    fakebuild, tenant=build_set.item.pipeline.tenant.name,
-                    final=True)
-            except Exception:
-                log.exception("Error reporting build completion to DB:")
+            build_set.item.setNodeRequestFailure(job)
             self._resumeBuilds(build_set)
             tenant = build_set.item.pipeline.tenant
             tenant.semaphore_handler.release(