[TEST] pre check download service working

Seen during CI tests, it could appears that the download service is not available for any reason.

This fix in test will check before each test which requires an internet access (annotated with @Network) that the download service we are testing is still working.

It won't fail the test but will mark the test as `Ignored` in case of failure.
(cherry picked from commit 2af19a4)
(cherry picked from commit 099142c)
(cherry picked from commit 56b6b85)
Enforce query instance checking before it wrapper as a filter

We have the default QueryWrapperFilter as well as our custom one while
our wrapper is explicitly marked as no_cache such that it will never
be included in a cache. This was not consistenly used and caused several
problems during tests where p/c related queries were used as filters
and ended up in the cache. This commit adds the QueryWrapperFilter
ctor to the forbidden APIs to enforce the query instance checks.
Improve exception handling in HttpDownloadHelper
[DOCS] Documented gateway.local.auto_import_dangled

Relates to #4996
Count latch down if sendsPing throws exception

if the async sendPingsHandler throws an unexpected exception the
corresponding latch is never counted down. This might only happen
during node shutdown but can still cause starvation or test failures.
[Test] IndexLifecycleActionTests - set minimum master node earlier to make sure it's in effect when needed.
[Test] FullRollingRestartTests - correctly setting minimum_master_nodes

Also added a ElasticsearchIntegrationTest.setMinimumMasterNodes() helper function.
[Tests] QuorumLocalGatewayTests - Set mini_master_nodes earlier to make sure it has effect.  ClusterServiceTests - remove a thread.sleep in favor of awaitBusy
[DOCS] Reword clear-scroll sentence
[DOCS] Fixing contributing.md indentation

Add a whitespace to make these separate paragraphs inside of a list.
Move systemd files from /etc to /usr/lib

As documented in systemd's manual pages tmpfiles.d(5) and systemd.unit(5),
a package should install its default configuration in /usr/lib, which can
be overriden by system administrators in /etc.

New locations in the rpm:
/usr/lib/systemd/system/elasticsearch.service
/usr/lib/tmpfiles.d/elasticsearch.conf
[TEST] Print tests.jvms and tests.client.ratio if set

We need to print options that can modify stream of events we need
to print it otherwise a seed might not reproduce the failure in
the tests.
[TEST] pre check download service working

Seen during CI tests, it could appears that the download service is not available for any reason.

This fix in test will check before each test which requires an internet access (annotated with @Network) that the download service we are testing is still working.

It won't fail the test but will mark the test as `Ignored` in case of failure.
(cherry picked from commit 8dfdc6f)
Geo Point Fieldmapper: Allow distance for geohash precision

Even though mentioned differently in the docs, the geohash precision needed to
be an integer instead of a DistanceUnit.

Closes #5448
[Test] RecoveryWhileUnderLoadTests: smarter waiting for background indexers as it sometimes times out.