Remove searchSource from tile_map visualization

[lukeelmers]

Right now, coordinate_maps_visualization.js uses searchSource to query for geohash bounds whenever the "Fit to bounds" map icon is clicked.

Ideally visualizations should not be using searchSource at all, and should only be relying on the dataLoader to pass them all of the information they need.

This is the only vis type I am aware of that's using searchSource from within the vis itself, and it has forced us to add some hacky workarounds for passing global query/filter state down to the vis (e.g. #30595).

Goals for this work would be:

1. Implement a solution to replace getGeohashBounds() in coordinate_maps_visualization.js, removing searchSource and managing it outside of the vis.
2. Remove the global state data that we are tacking on to the vis object in embedded_visualize_handler. This was a one-off solution to a bug affecting the tile_map vis ("Fit Data Bounds" neglects filter settings #23261).

[elasticmachine]

Pinging @elastic/kibana-app

[lukeelmers]

closing as this has already been removed