NXCALS-4044 Fix slow processing of HierarchyService#findAll method with RSQL statement

Merge request template

Temporary playground server on TESTBED: https://cs-ccr-nxcalstbs1.cern.ch:18094

1) Find all top hierarchy nodes (was 15,447 seconds!) now -> 900ms

2020-07-22 22:03:21.263 [DEBUG] [main] HierarchyClient - [HierarchyClient#findAll] <--- HTTP/1.1 200 (667ms)
Stop
duration ms: 860

2) Find all hierarchies by name like "A%" (was 11,261 seconds!) now -> 208ms

2020-07-22 20:49:18.861 [DEBUG] [main] HierarchyClient - [HierarchyClient#findAll] <--- HTTP/1.1 200 (156ms)
Stop
duration ms: 208

COMPATIBILITY NOTE

Please make sure that this change is BACKWARDS COMPATIBLE and a new server will work correctly with clients using old APIs versions.

It may be that data sent in the new format will break the old clients.

In case of any potential incompatibility we have to inform our clients and schedule release & deployment with them.

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@acc-logging-team - please have a look for approval.

Please describe the merge request here.

Closes NXCALS-4044