Geo Status Page 2.0 - Vuex Store

Vision

Based on proposal described here: &4712 (closed)
Code to ultimately be replaced: https://gitlab.com/gitlab-org/gitlab/-/tree/master/ee/app/assets/javascripts/geo_nodes

This issue will be focused on creating the Vuex store that mimics the goals and functionality from the current geo/nodes/store/geo_nodes_store, geo/nodes/service/geo_nodes_service.js and geo/nodes/event_hub.js.

What is needed

1. index.js (This will initialize the store).
2. actions.js (This will contain all the actions and should provide similar functionality to geo/nodes/service/geo_nodes_service.js and geo/nodes/event_hub.js).
3. getters.js (This will contain all the data modeling that is done via geo/nodes/store/geo_nodes_store).
4. mutations.js (This will handle the state management provided in geo/nodes/store/geo_nodes_store).
5. mutation_types.js (This works in tandem with mutations.js to manage all the mutation names).
6. state.js (This will store all the data values previously stored in geo/nodes/store/geo_nodes_store).

This issue is focused on creating the store. There won't be any usage in the UI until the following issue.