Adds a link to the cloud deployment when there are no nodes and kibana is running on cloud.

Text in callout

No ML nodes available
There are no ML nodes available.
You will not be able to create or run jobs.
Please edit your Elastic Cloud deployment and enable a machine learning node.

Can be tested by adding some settings to yml files:
elasticsearch.yml
node.ml: false

kibana.yml
xpack.cloud.id: <supply your own cloud id>

Also moves some code about:
removes new_job_defaults.ts in favour of /services/ml_server_info
renames the function loadNewJobDefaults to loadMlServerInfo as more than just new job defaults are being loaded.
new_job_defaults was being deep linked to from other files, so it's best that it's moved to a common location. it also makes sense that the cloud checks to added to this file.

Checklist

Use strikethroughs to remove checklist items you don't feel are applicable to this PR.

- [ ] This was checked for cross-browser compatibility, including a check against IE11

• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
  - [ ] Documentation was added for features that require explanation or tutorials
• Unit or functional tests were updated or added to match the most common scenarios
  - [ ] This was checked for keyboard-only and screenreader accessibility

For maintainers

- [ ] This was checked for breaking API changes and was labeled appropriately
- [ ] This includes a feature addition or change that requires a release note and was labeled appropriately