[ML] Job Management: Keep selected page size

[elasticmachine]

Original comment by @cwurm:

Describe the feature:
The ML Job configuration view has a Page Size drop-down. However, whenever a job is changed (Edit Job, Delete Job, etc.), it is reset to 10.

I was just organizing my jobs - renaming some, deleting some old ones - and every time I did that to one of the jobs that was not in the first 10 I had to change the page size again.

I later realized the page one is on does remain the same and so I could have saved myself some headache there. Nevertheless, the page size setting should persist I think.

[elasticmachine]

Original comment by @jgowdyelastic:

The jobs list is to be rewritten using an euiTable, as soon as it supports row expansion (elastic/eui#466).
Once this happens we can see about persisting the row count. It might come for free with euiTable by then (fingers crossed).

[peteharverson]

This will be fixed as part of the work in #20150

[sophiec20]

Resolved with #20150. Closing.