Add "Need an API Key?" link that opens in a new tab

[colearendt]

When defining a new Connect server:

I oftentimes have to go create an API key for this context. This requires a lot of "know-how" from the user. If / when the Connect server is defined (see #217), if there was a link to "Go Create an API Key" that takes you to your personal Connect API key page, I suspect it would simplify the user experience tremendously.

I suspect:
(1) Before the Connect URL is set, maybe we have it greyed out with a tooltip "Define your Connect Server URL first"
(2) When the Connect URL is set, should we validate it in the UI? "This does not look like a valid Connect URL." One common pain point that we see in R, at least, is people include /connect in the URL
(3) I realize now that the /apikeys URL is beneath the user (i.e. https://colorado.rstudio.com/rsc/connect/#/people/users/GUID/apikeys), so perhaps this requires a product feature that is a global /connect/apikey redirect that (A) prompts for authentication and then (B) redirects you to your personal user /apikeys URL