[UI] Get the namespace from the user info for run iFrame

[ckadner]

trafficstars

When we support multiple users in the future, beyond admin and unauthenticated users, we will need to get the namespace from the user info for the Pipeline Run and View Experiments iFrame

https://github.com/machine-learning-exchange/mlx/blob/bbcf7e1d99db97330471d22bcc8789b21dd92a70/dashboard/origin-mlx/src/App.tsx#L69-L70

Originally posted by @ckadner in https://github.com/machine-learning-exchange/mlx/pull/252#discussion_r739404583

[ckadner]

FYI @yhwang @Tomcli

[yhwang]

and also the experiment view iFrame :-)

[yhwang]

and maybe figure out if we can use just one iFrame for both of them. my guess is yes