[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.
Scan: Use ConcurrentHashMap instead of HashMap, because the readerStates is accessed by multiple threads during the entire scroll session.

Closes #7499
Closes #7478