[Enhancement] - Use Autocomplete for Sign-up page

[AJSterner]

Describe the Current Behavior/Feature:

You currently need to type out the entire url for a pod provider in the sign up page.

Rationale:

We should give users the option to select a previously known provider without having to find the url externally or typing it all out.

Proposed Changes:

Add an autocomplete dropdown for pod provider in the existing pods.

Possible Drawbacks:

We'll need to add additional servers to the list as they are added. There may be additional complexity

Alternatives Considered:

...

Additional Context:

We currently already have a server autocomplete in the nav bar