Account for runners with multiple IP addresses

What does this MR do and why?

Account for runners with multiple IP addresses

When there are groups of runners, the runner managers may have different IP addresses.

This change accounts for multiple IP addresses across runner managers, by showing the IP address field to be the first registered runner manager with plus indicator for more.

Changelog: changed

Screenshots or screen recordings

Account for more than 1 IP with: 127.0.0.1 (+1).

Before	After

How to set up and validate locally

You may not have enough runner managers to test the runners you use. We want to simulate having two separate machines with runner installed:

Install runner locally

1. brew install runner works on MacOS

Follow the instructions to create a runner

1. Admin -> Runners
2. Select "Create instance runner"
3. Ensure you run the gitlab-runner register ... step

Simulate two machines

1. Duplicate the configuration files cp -R ~/.gitlab-runner ~/.gitlab-runner-2
2. Edit the random system id open ~/.gitlab-runner-2/.runner_system_id (changing one character will do)
3. Run runner 1 gitlab-runner run
   • the default configuration at ~/.gitlab-runner will be used
4. In another console tab, run runner 2 gitlab-runner run --config ~/.gitlab-runner-2/config.toml

Confirm the item in the list

1. Admin -> Runners
2. Check the list for the newly created runner

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #411948 (closed)