zubhub (feat): Improve search for non-logged-in users

Summary

This PR addresses the intended flow explained here. Now, logged-out users can search for projects and creators

Closes #802

Changes

Although this PR is to make changes for non-logged-in users, I kept some of the changes that also affect logged-in user's experience but can remove them upon your comments.

For non-logged-in users:

Search dropdown is disabled
If the query matches with multiple results, they only see 3 of them at most
they see a login form when they make search with or without results
If there are no results, 3 staff pick projects are shown instead (only for project search)

For logged-in users:

They also see the staff pick projects when their project search yields no results
When they make a creator search with no results, they see the same page with non-logged-in users except for the login form

To Do

[ ] Make the results' paths directly accessible by non-loggers but limit the other projects/creators

Screenshots

Please see how results look for different combinations here

Here is a quick demonstration of how search looks like for an unauthenticated user:

https://github.com/unstructuredstudio/zubhub/assets/92817363/b752b529-ce30-43d1-ad26-f114abca8c72

Further Improvement

There are some things to be improved for the overall search feature, which can be a part of another PR. Some of them are:

Currently, tag search is not possible
Styles should be made more unified since there are a lot of inconsistencies
Searching for projects or creators is not possible unless the user types a whole word (e.g. searching for '' does not work)