This commit adds a conversion function from numerics (and aggregate
metric doubles) to aggregate metric doubles.
It is most useful when you have multiple indices, where one index uses
aggregate metric double (e.g. a downsampled index) and another uses a
normal numeric type like long or double (e.g. an index prior to
downsampling).
Earlier work on the ES|QL port of docs to V3 introduced an issue in the build.gradle file making it fail with --configuration-cache. This fixes that, as well as one other broken link and removes some unused files.
In addition we bring back partial support for deleting unused files. It is tricky to have full support for this due to the mix of static and generated content, particularly in the operators snippets.
In a few previous PR's we restructured the ES|QL docs to make it possible to generate them dynamically.
This PR just moves a few files around to make the query languages docs easier to work with, and a little more organized like the ES|QL docs.
A bit part of this was setting up redirects to the new locations, so other repo's could correctly link to the elasticsearch docs.
Building on the work started in https://github.com/elastic/elasticsearch/pull/123904, we now want to auto-generate most of the small subfiles from the ES|QL functions unit tests.
This work also investigates any remaining discrepancies between the original asciidoc version and the new markdown, and tries to minimize differences so the docs do not look too different.
The kibana json and markdown files are moved to a new location, and the operator docs are a little more generated than before (although still largely manual).
