Update Completions for transform in dev console

[hendrikmuhs]

Describe the feature:

Transform has updated its configuration and e.g. added settings to it for 7.8. Because the REST specs do not contain the body, these need to updated manually.

Affected API's:

https://www.elastic.co/guide/en/elasticsearch/reference/7.8/put-transform.html
https://www.elastic.co/guide/en/elasticsearch/reference/7.8/preview-transform.html
https://www.elastic.co/guide/en/elasticsearch/reference/7.8/update-transform.html

Describe a specific use case for the feature:

Using the dev console is extremely useful for experienced users. We developed a nice UI around transform, however at some point advanced users want to switch to the console. Completions give them a nice work environment and make options more visible.

/CC @jloleysens Let me know if you need anything else.

[elasticmachine]

Pinging @elastic/es-ui (Team:Elasticsearch UI)

[jloleysens]

Thanks for the update @hendrikmuhs .

@cuff-links could you take this into consideration for the current bout of updates?

[cuff-links]

@jloleysens Thanks for the ping. Yes, I will include these.

[cuff-links]

This has been done. Fixed by #66630