This commit moves the range field mapper back to core so that we can
remove the compile-time dependency of percolator on mapper-extras which
compilcates dependency management for the percolator client JAR, and
modules should not be intertwined like this anyway.
Relates #27854
Today we have all non-plugin mappers in core. I'd like to start moving those
that neither map to json datatypes nor are very frequently used like `date` or
`ip` to a module.
This commit creates a new module called `mappers-extra` and moves the
`scaled_float` and `token_count` mappers to it. I'd like to eventually move
`range` fields there but it's more complicated due to their intimate
relationship with range queries.
Relates #10368
* Add parent-join module
This change adds a new module named `parent-join`.
The goal of this module is to provide a replacement for the `_parent` field but as a first step this change only moves the `has_child`, `has_parent` queries and the `children` aggregation to this module.
These queries and aggregations are no longer in core but they are deployed by default as a module.
Relates #20257
Significant changes:
* AbstractQueryTestCase has moved to the test framework module, in order for query builder tests in modules and plugins
* Added support to AbstractQueryTestCase to register plugins
* Lift the restriction that only one percolator could be added per index. This validation existed in MapperService, but because the percolator moved to a module it could no longer exist there. Instead of bringing it back it was removed. This validation existed since the percolator cache only supported one percolator query per document, since the percolator cache has been removed this restriction could removed as well.
* While moving percolator tests to the new module, also removed a couple of tests for the deprecated percolate and mpercolate api. These APIs are now sugar APIs for bwc and rediect to the searvh and msearvh APIs. Some tests were still testing as if percolate and mpercolate API did the percolation, but this no longer the case and these tests could be removed.