Dashboard: Allows the d-solo route to be used without slug

[97amarnathk]

Removes the :slug fromt the routes and the API. This allows the Embedded URLs to work without requiring the dashboard name.

Which issue(s) this PR fixes:

Fixes #11617

[marefr]

Some changes still needed.

[CLAassistant]

All committers have signed the CLA.

[marefr]

Great. Works as expected

[marefr]

@97amarnathk Thank you for contributing to Grafana!

Totally optional, but may I ask you if you're participating in Hacktoberfest and whether you've find this issue through the hacktoberfest label? Trying to find out if new contributors are finding Grafana due to Hacktoberfest.

[97amarnathk]

@marefr
Actually I started reading up on Go/Prometheus, and therefore Grafana came in my Github repositories reccomendation. Added to this, Hacktoberfest provided me motivation to get started with Grafana.

P.S. Can I get an issue to solve ? Something which is a bit more involved but has a sufficient enough learning curve for a beginner in Grafana and Go?

[marefr]

@97amarnathk thanks, that's great 😄

Maybe you can have a look here or here for issues that's labeled help wanted. Write a comment in an issue you would like to work on or are interested in and we'll get back to you with some additional pointers.