dashboard: allow filtering users in "make request as" feature of graphql section

[spakanati]

Is your feature request related to a problem? Please describe.
The "Make request as" feature of the Nhost dashboard is very convenient for being able to mimic making a request as a specific user. However, in real-world use it's almost impossible to use because the list of users is just a giant dropdown.

Describe the solution you'd like
There should be a search or filter that allows you to search by user ID (or email, display name, etc.).

Describe alternatives you've considered
n/a

Additional context
n/a