Third party Lens visualization

To run this example plugin, use the command yarn start --run-examples.

This example shows how to register a visualization to Lens which lives along the regular visualizations (xy, table and so on).

The following parts can be seen in this example:

Registering the visualization type so it shows up in the Lens editor along with custom edit UI and hooks to update state on user interactions (add dimension, delete dimension).
Registering the used expression functions and expression renderers to actually render the expression into a DOM element.
Providing a sample migration on the Kibana server which allows to update existing stored visualizations and change their state on Kibana upgrade / import of old saved objects.

To test the migration, you can import the following ndjson file via saved object import (requires installed logs sample data):

<details> <summary>Click to expand</summary>

{"attributes":{"fieldFormatMap":"{\"hour_of_day\":{}}","runtimeFieldMap":"{\"hour_of_day\":{\"type\":\"long\",\"script\":{\"source\":\"emit(doc['timestamp'].value.getHour());\"}}}","timeFieldName":"timestamp","title":"kibana_sample_data_logs"},"coreMigrationVersion":"8.0.0","id":"90943e30-9a47-11e8-b64d-95841ca0b247","migrationVersion":{"index-pattern":"8.0.0"},"references":[],"type":"index-pattern","updated_at":"2022-01-24T10:54:24.209Z","version":"WzQzMTQ3LDFd"}
{"attributes":{"description":"","state":{"datasourceStates":{"formBased":{"layers":{"f2700077-50bf-48e4-829c-f695f87e226d":{"columnOrder":["5e704cac-8490-457a-b635-01f3a5a132b7"],"columns":{"5e704cac-8490-457a-b635-01f3a5a132b7":{"dataType":"number","isBucketed":false,"label":"Count of records","operationType":"count","scale":"ratio","sourceField":"Records"}},"incompleteColumns":{}}}}},"filters":[],"query":{"language":"kuery","query":""},"visualization":{"column":"5e704cac-8490-457a-b635-01f3a5a132b7","layerId":"f2700077-50bf-48e4-829c-f695f87e226d"}},"title":"Rotating number test","visualizationType":"rotatingNumber"},"coreMigrationVersion":"8.0.0","id":"468f0be0-7e86-11ec-9739-d570ffd3fbe4","migrationVersion":{"lens":"8.0.0"},"references":[{"id":"90943e30-9a47-11e8-b64d-95841ca0b247","name":"indexpattern-datasource-current-indexpattern","type":"index-pattern"},{"id":"90943e30-9a47-11e8-b64d-95841ca0b247","name":"indexpattern-datasource-layer-f2700077-50bf-48e4-829c-f695f87e226d","type":"index-pattern"}],"type":"lens","updated_at":"2022-01-26T08:59:31.618Z","version":"WzQzNjUzLDFd"}
{"excludedObjects":[],"excludedObjectsCount":0,"exportedCount":2,"missingRefCount":0,"missingReferences":[]}

</details>