[Uptime] Application cannot handle named locations with no geo data

[justinkambic]

Kibana version:
master

Elasticsearch version:
master

Server OS version:
macOS

Browser version:
Chrome 79.x

Browser OS version:
macOS

Original install method (e.g. download page, yum, from source, etc.):
from source

Describe the bug:
While reviewing #55177 I discovered an issue that causes our application to cease functioning within normal parameters. In this configuration, there are several fields that are assumed to be present that are optional. This causes function calls and other references to undefined.

Steps to reproduce:

1. Configure a heartbeat monitor with a location name, but no geo data.
2. Navigate to Uptime
3. Navigate to the monitor page
4. Observe the errors logged by the server

Expected behavior:
There would be no reference to these fields that would cause errors or strange behavior.

Screenshots (if relevant):

Errors in browser console (if relevant):

Provide logs and/or server output (if relevant):

Any additional context:

[elasticmachine]

Pinging @elastic/uptime (Team:uptime)