* ui: Convert Service.GatewayConfig to a model fragment
We added the ember-intl addon, which has its own format-number helper.
We replaced our own similarly named helper with this one, but the
ember-intl one is far stricter and errors if the arguments passed are
undefined. Our previously one would cope with this.
We'd rather continue to use the stricter ember-intl helper, so here we
convert the GatewayConfig property to a model fragment so that we can
give the GatewayConfig.AssociatedServices property a default zero value.
This PR updates the tags that we generate for Envoy stats.
Several of these come with breaking changes, since we can't keep two stats prefixes for a filter.
* ui: Add functionality to metrics mocks:
1. More randomness during blocking queries
2. NaN and undefined values that come from prometheus
3. General trivial amends to bring things closer to the style of the
project
* Provider should always provide data as a string or undefined
* Use a placeholder `-` if the metrics endpoint responds with undefined data
* Add consul-api-double under api
* Update config to reflect api change
* Remove consul-api-double as a dependency
* api -> mock-api
* Fixup mocks path for staging