Allow for field selection in the search endpoint

[bhermann]

Is your feature request related to a problem? Please describe.
Currently, search queries only return data on the queried fields. With this issue, we would like to give users control over the returned fields.
For example:

[metrics.api.unsafe.heapget] > 0 #[metrics.bytecode.*] 

Describe the solution you'd like
This example should return projects with Unsafe Heap Get operations. For these projects metrics.api.unsafe.heapget is returned, but also any metric prefixed with metrics.bytecode..

For this, this syntax first needs to be amended as describe in delphi-hub/delphi-core#2 .

Describe alternatives you've considered
none

Additional context
none

[bhermann]

Closed with v0.9.5