Possibility to use free text search for categories and scopes

**Is your feature request related to a problem? Please describe.**

We have received feedback from actual users that they have tried to search their proposals using the free text search by writing the category or scope they remember marking their proposal with.

They have failed to find their proposals through this method.

**Describe the solution you'd like**

The category and scope names should be included in the free text search to make this possible.

**Describe alternatives you've considered**

Instructing the users is always a possibility but it would greatly help users if they are provided with the tools they expect to work and they are used to using other services online, such as Google or Facebook.

**Additional context**

**Does this issue could impact on users private data?**

No.