This replaces the original #76526 due to merge errors.

Summary

Adds super-fine option to grids/clusters and heatmaps layers. This uses vector-tiles as the back-end data format.

Addition of the super-fine option

The super-fine option currently returns tiles with a resolution of 128x128 = ((2^7)^2) . This is well under the limit of 256x256 of Elasticsearch.

Making this much finer though will start to create sparsity-artefacts when zooming in on data. This probably needs some experimentation.

Adds a new backend route mvt/getGridTile

This produces the tile. It either returns a tile with cluster-bubbles or with rectangular cells, depending on the ESGeoGridSourceDescriptor.requestType-configuration.

Moved ES-response decoding utils to common for reuse on server-backend.

Enabled for grid and cluster layer

(not heatmap just yet)

ESGeoGridSource now implements ITiledSingleLayerVectorSource

Styling limitation on countable-metrics

Countable metrics cannot be auto-styled using a backend meta-call for ES extented-stats This runs into a similar limitation as for 3rd party vector tiles, where colors can only be configured with custom-ranges (iso. default color-ramps) and that size cannot be styled by-value (cf. #62867).

Checklist

Delete any items that are not applicable to this PR.

• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• [ ] Documentation was added for features that require explanation or tutorials
• Unit or functional tests were updated or added to match the most common scenarios
• This was checked for keyboard-only and screenreader accessibility
• This renders correctly on smaller devices using a responsive layout. (You can test this in your browser
• This was checked for cross-browser compatibility

For maintainers

• This was checked for breaking API changes and was labeled appropriately

Todo

• test coverage
• top-terms styling not working (edge-case in how the use of supportsAutoDomain is overloaded)
• linting
• type checking