Store the number of datasets available in the catalog after a query

[mosoriob]

When a user queries our data catalog, we currently display the search results but we do not store the number of datasets available in the catalog. We should store this number for future reference and to provide better search functionality.

Therefore, I propose that we add a feature that stores the number of datasets available in the catalog after each query. This feature will make it easier for users to determine the relevance of their search results and refine their queries.

Additionally, this feature will also enable us to analyze our data catalog usage patterns and optimize our search algorithms accordingly.

Tasks:

Add a new variable to store the number of datasets available in the catalog after each query.
Modify the code to update this variable after each query.
Add the capability to display the total number of datasets available in the catalog to the user.
Write tests to ensure that the new feature works as expected.
This feature will improve the usability and functionality of our data catalog, and I believe it should be a priority for the next release.