This commit adds a script parameter to long and double fields that makes
it possible to calculate a value for these fields at index time. It uses the same
script context as the equivalent runtime fields, and allows for multiple index-time
scripted fields to cross-refer while still checking for indirection loops.
Runtime fields currently live in their own java package. This is really
a leftover from when they were in their own module; now that they are
in core they should instead live in the common packages for classes of
their kind.
This commit makes the following moves:
org.elasticsearch.runtimefields.mapper => org.elasticsearch.index.mapper
org.elasticsearch.runtimefields.fielddata => org.elasticsearch.index.fielddata
org.elasticsearch.runtimefields.query => org.elasticsearch.search.runtime
The XFieldScript fields are moved out of the `mapper` package into
org.elasticsearch.scripts, and the `PARSE_FROM_SOURCE` default scripts
are moved from these Script classes directly into the field type classes that
use them.
The runtime fields yaml tests are part of the x-pack yaml test suite, but the runtime fields code has been moved to server. This commit moves the yaml tests to the runtime-fields-common module. The reason why all the tests are moved to the module (rather than only the grok and dissect one which the module provides) is that painless is not available in the ordinary yaml tests and these tests rely on painless heavily.
The only tests that are left behind are the telemetry ones, as telemetry is the last bit that needs to be migrated.
As a follow-up of moving runtime fields to server, we'd like to remove the xpack plugin portions that are left. One part of this is the grok and dissect implementation which depends on grok and dissect libraries that painless does not have available. A new runtime-fields-common module is created to hold their implementations and plug in the necessary whitelists.
