* Migrate scripted metric aggregation scripts to ScriptContext design #29328
* Rename new script context container class and add clarifying comments to remaining references to params._agg(s)
* Misc cleanup: make mock metric agg script inner classes static
* Move _score to an accessor rather than an arg for scripted metric agg scripts
This causes the score to be evaluated only when it's used.
* Documentation changes for params._agg -> agg
* Migration doc addition for scripted metric aggs _agg object change
* Rename "agg" Scripted Metric Aggregation script context variable to "state"
* Rename a private base class from ...Agg to ...State that I missed in my last commit
* Clean up imports after merge
Allowing `_doc` as a type will enable users to make the transition to 7.0
smoother since the index APIs will be `PUT index/_doc/id` and `POST index/_doc`.
This also moves most of the documentation to `_doc` as a type name.
Closes#27750Closes#27751
This commit adds back "id" as the key within a script to specify a
stored script (which with file scripts now gone is no longer ambiguous).
It also adds "source" as a replacement for "code". This is in an attempt
to normalize how scripts are specified across both put stored scripts and script usages, including search template requests. This also deprecates the old inline/stored keys.
This change unifies the way scripts and templates are specified for all instances in the codebase. It builds on the Script class added previously and adds request building and parsing support as well as the ability to transfer script objects between nodes. It also adds a Template class which aims to provide the same functionality for template APIs
Closes#11091