and modify data-structure of `include_keys` and `exclude_keys` to be
backed by a HashSet

* master:
  Add support for clear scroll to high level REST client (elastic#25038)
  Tiny correction in inner-hits.asciidoc (elastic#25066)
  Added release notes for 6.0.0-alpha2
  Expand index expressions against indices only when managing aliases (elastic#23997)
  Collapse inner hits rest test should not skip 5.x
  Settings: Fix secure settings by prefix (elastic#25064)
  add `exclude_keys` option to KeyValueProcessor (elastic#24876)
  Test: update missing body tests to run against versions >= 5.5.0
  Track EWMA[1] of task execution time in search threadpool executor
  Removes an invalid assert in resizing big arrays which does not always hold (resizing can result in a smaller size than the current size, while the assert attempted to verify the new size is always greater than the current).
  Fixed NPEs caused by requests without content. (elastic#23497)
  Plugins can register pre-configured char filters (elastic#25000)
  Build: Allow preserving shared dir (elastic#24962)
  Tests: Make secure settings available from settings builder for tests (elastic#25037)

* master: (1210 commits)
  Add support for clear scroll to high level REST client (elastic#25038)
  Tiny correction in inner-hits.asciidoc (elastic#25066)
  Added release notes for 6.0.0-alpha2
  Expand index expressions against indices only when managing aliases (elastic#23997)
  Collapse inner hits rest test should not skip 5.x
  Settings: Fix secure settings by prefix (elastic#25064)
  add `exclude_keys` option to KeyValueProcessor (elastic#24876)
  Test: update missing body tests to run against versions >= 5.5.0
  Track EWMA[1] of task execution time in search threadpool executor
  Removes an invalid assert in resizing big arrays which does not always hold (resizing can result in a smaller size than the current size, while the assert attempted to verify the new size is always greater than the current).
  Fixed NPEs caused by requests without content. (elastic#23497)
  Plugins can register pre-configured char filters (elastic#25000)
  Build: Allow preserving shared dir (elastic#24962)
  Tests: Make secure settings available from settings builder for tests (elastic#25037)
  [TEST] Skip wildcard expansion test due to breaking change
  Test that gradle and Java version types match (elastic#24943)
  Include duplicate jar when jarhell check fails
  Change ScriptContexts to use needs instead of uses$. (elastic#25036)
  Change `has_child`, `has_parent` queries and `childen` aggregation to work with the new join field type and at the same time maintaining support for the `_parent` meta field type.
  Remove comma-separated feature parsing for GetIndicesAction
  ...

* master: (619 commits)
  Add support for clear scroll to high level REST client (elastic#25038)
  Tiny correction in inner-hits.asciidoc (elastic#25066)
  Added release notes for 6.0.0-alpha2
  Expand index expressions against indices only when managing aliases (elastic#23997)
  Collapse inner hits rest test should not skip 5.x
  Settings: Fix secure settings by prefix (elastic#25064)
  add `exclude_keys` option to KeyValueProcessor (elastic#24876)
  Test: update missing body tests to run against versions >= 5.5.0
  Track EWMA[1] of task execution time in search threadpool executor
  Removes an invalid assert in resizing big arrays which does not always hold (resizing can result in a smaller size than the current size, while the assert attempted to verify the new size is always greater than the current).
  Fixed NPEs caused by requests without content. (elastic#23497)
  Plugins can register pre-configured char filters (elastic#25000)
  Build: Allow preserving shared dir (elastic#24962)
  Tests: Make secure settings available from settings builder for tests (elastic#25037)
  [TEST] Skip wildcard expansion test due to breaking change
  Test that gradle and Java version types match (elastic#24943)
  Include duplicate jar when jarhell check fails
  Change ScriptContexts to use needs instead of uses$. (elastic#25036)
  Change `has_child`, `has_parent` queries and `childen` aggregation to work with the new join field type and at the same time maintaining support for the `_parent` meta field type.
  Remove comma-separated feature parsing for GetIndicesAction
  ...