The parsing code for script query currently silently skips by any tokens
it does not know about within its parsing loop. The only token it does
not catch is an array, which means pasing multiple scripts in via an
array will cause the last script to be parsed and one, silently dropping
the others. This commit adds validation that arrays are not seen while
parsing.

* master: (80 commits)
  Remove HTTP max content length leniency (elastic#29337)
  Begin moving XContent to a separate lib/artifact (elastic#29300)
  Java versions for ci (elastic#29320)
  Minor cleanup in the InternalEngine (elastic#29241)
  Clarify expectations of false positives/negatives (elastic#27964)
  Update docs on vertex ordering (elastic#27963)
  Revert "REST high-level client: add support for Indices Update Settings API (elastic#28892)" (elastic#29323)
  [test] remove Streamable serde assertions (elastic#29307)
  Improve query string docs (elastic#28882)
  fix query string example for boolean query (elastic#28881)
  Resolve unchecked cast warnings introduced with elastic#28892
  REST high-level client: add support for Indices Update Settings API (elastic#28892)
  Search: Validate script query is run with a single script (elastic#29304)
  [DOCS] Added info on WGS-84. Closes issue elastic#3590 (elastic#29305)
  Increase timeout on Netty client latch for tests
  Build: Use branch specific refspec sysprop for bwc builds (elastic#29299)
  TEST: trim unsafe commits before opening engine
  Move trimming unsafe commits from engine ctor to store (elastic#29260)
  Fix incorrect geohash for lat 90, lon 180 (elastic#29256)
  Do not load global state when deleting a snapshot (elastic#29278)
  ...