[keyserver] Include initial navInfo selectedUserList

Summary:
If you navigate directly to an url for chat creation we want to include the mentioned users infos in the nav info.

Depends on D8011

Test Plan: Navigate to /chat/create/<user-not-in-userstore> and /chat/create/<user-in-userstore> and check if they both work correctly

Reviewers: kamil, inka, ashoat

Reviewed By: ashoat

Subscribers: ashoat, tomek, atul

Differential Revision: https://phab.comm.dev/D8012