[Tests] change BasicBackwardsCompatibilityTest to be compatible with 1.0.3

Also increase the time we wait for an external node to join
Sadly tests are not yet stable enough, testing with 1.0.3 is still disabled
[Internal] user node's cluster name as a default for an incoming cluster state who misses it

ClusterState has a reference to the cluster name since version 1.1.0 (df7474b9fcf849bbfea4222c1d2aa58b6669e52a) . However, if the state was  sent from a master of an older version, this name can be set to null. This is an unexpected and can cause bugs. The bad part is that it will never correct it self until a full cluster restart where the cluster state is rebuilt using the code of the latest version.

This commit changes the default to the node's cluster name.

Relates to #7386

Closes #7414
Introduced FixedBitSetFilterCache that guarantees to produce a FixedBitSet and does evict based on size or time.
Only when segments are merged away due to merging then entries in this cache are cleaned up.

Nested and parent/child rely on the fact that type filters produce a FixedBitSet, the FixedBitSetFilterCache does this.
Also if nested and parent/child is configured the type filters are eagerly loaded by default via the FixedBitSetFilterCache.

Closes #7037
Closes #7031
[SNAPSHOT] Ensure BWC layer can read chunked blobs
FunctionScore: Fixed RandomScoreFunction to guard against _uid field not existing.

Also added a test case to check the random score works with queries on
an empty index.
Spelling error of aggregation
[TEST] use a dedicated port range per test JVM

For reliability and debug purposes each test JVM should use it's own
TCP port range if executed in parallel. This also moves away from the
default port range to prevent conflicts with running ES instance on the local
machine.
[TEST] only expand to 1 replica in SnapshotBackwardsCompatibilityTest
Test: Increase the ping timeout to avoid that a candidate master node makes the decision to elect itself too soon.
[Tests] add a debug logging message when starting an external node
[TEST] Fix RandomScoreFunctionTests#testConsistentHitsWithSameSeed
[CORE] Make network interface iteration order consistent

Today the iteration order of the interfaces might change across JVMs
this commit cleans up the NetworkUtils class and attempts to ensure
consistent iteration order across JVMs.
Validate create index requests' number of primary/replica shards

Fixes #7495
test: write heap dump to log folder

Per default the heap dump is written to target/JX/pidXYZ.hprof
In order to keep them when a new test is is started, they
should be written to log folder which is not cleared in a new
test run.
Heap dump location can be set with -Dtests.heapdump.path=/path/to/heapdump

closes #7452
[TEST] apply default settings before test specific ones to external nodes in bw comp tests, otherwise the defaults win all the time
[TEST] make default settings don't override test specific settings
[TEST] apply default settings by calling super.nodeSettings method when providing test specific methods
Indexed Scripts/Templates : Fix .script index template.

This commit makes the default number of shards for the .scripts index to ````1````, it also
forces the auto_expand replicas to ````1-all````. This change means that script index GET requests to load
scripts from the index should always use the local copy of the scripts index, preventing any network traffic or calls
on script GET.
Indexed Scripts/Templates : Change the default auto_expand to 0-all

This commit changes the auto_expand_replicas setting for the ````.scripts```` index to
0-all from 1-all.
Aggregations: Encapsulate AggregationBuilder name and make getter public

Close #7425