feat: Add folderUID and folderRef in GrafanaDashboard CRD

[aboulay-numspot]

Aim of the merge request

This MR aims to implement the content of the document discussed in maintainer meeting (currently under #1592).

The features are the following:
If folder is set and none of the other fields is set (backwards compat. case): Create the folder
If folderUID or folderRef is set, don't create the folder
If folderUID or folderRef AND folder is set, the new fields take priority -> don't create the folder

Breaking change

There is no breaking change. We implement on the top of existing GrafanaDashboard CR behavior.

[aboulay-numspot]

@theSuess - I know you are interested about this implementation. If it can help you to propose something even better, feel free to propose an evolution in a dedicated MR and close this one.

[theSuess]

Waiting for #1604 to be merged first as it introduces shared logic we can reuse here

[aboulay-numspot]

@theSuess I have updated the GrafanaDashboard CR to match with the interface. To do this, I have added a Condition block into the GrafanaDashboard.Status and add the state update into the Reconciliation loop. I removed the duplicated code with the interface developed in the GrafanaFolder MR (#1604).

Can you have a look on it? I don't understand the full meaning of the Condition object, I would be happy if someone can give me some feedback into this implementation.

I think I'm ready for a review this time.

[theSuess]

Thanks for updating this! I found a few minor nitpicks but looks great overall!