Include fetch phase of search query in the profiler

[Poojita-Raj]

Is your feature request related to a problem? Please describe.
In the profiler output, currently the time spent on the fetch phase of the query is not being measured.
The fetch phase of a search query is when the documents ids returned from the query phase are used to fetch the real documents.

This is an important step in the execution of a search request. By including the time spent here in the profile response, we get a better look into why a certain search request could be slow.

Describe the solution you'd like
Modify the profile response to include a fetch field that provides the user with total execution time spent on fetch phase of the query.

Describe alternatives you've considered
N/A

Additional context
#705