[EPM][Ingest] Use nicely formatted package title for display

[skh]

Currently, we use the package name for display in the data streams list (and possibly other places) that use the package information in the saved object epm-packages.

The registry also offers the nicer-to-read package title in the title field. In most cases this seems to be the package name capitalized, i.e. system vs. System, but there might be packages where the title can't be derived by capitalization.

This task is to add the title field to epm-packages and use it to display it in the UI:

• on the data streams list page
• check for other occurrences of this string that can be made prettier

[elasticmachine]

Pinging @elastic/ingest-management (Feature:EPM)