Switch from hash routing to path routing

[flash1293]

Currently all Kibana App apps are using hash routing, while the Kibana platform is leveraging path routing. To avoid complexity and instability, all hash routing should eventually be migrated to path routing.

Related: #65968

To make this transition as simple as possible, de-angularization should be completed first. Then react hash router can be replaced by an agnostic router component bound to the scoped history object passed in from the application service.

To make sure legacy links still work, it's important to provide backwards compatibility (forwarding a hash path to the right browser path when Kibana is opened). This can be implemented as a central utility function as part of the kibana_legacy plugin.

Subtasks

• Complete Discover de-angularization (Respective column in https://github.com/elastic/kibana/projects/44)
• Complete Visualize de-angularization (Deangularize Dashboard application #65614)
• Complete Dashboard de-angularization (Deangularize Dashboard application #65614)
• Complete Graph de-angularization
• Implement forwarding service / helper function

Actually cutting over can be approached separately for the individual apps:

• Discover
• Visualize
• Dashboard
• Lens
• Graph

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[stratoula]

This is done!