Support for $apply to perform groupBy in the queries

[AsjadMahmood]

Is your feature request related to a problem? Please describe.
I want to group some data based on a Gender, City etc and get count of the result

Describe the solution you'd like
A support for $apply through which we can apply groupBy with aggregate function like count,sum,avg etc.

Additional context
Similar to the aggregation extension that odata provides.
http://docs.oasis-open.org/odata/odata-data-aggregation-ext/v4.0/odata-data-aggregation-ext-v4.0.html

[Soontao]

sure, let me check this

[Soontao]

plan in next major release @odata/client@3.0

[Soontao]

after @odata/client@2.21.0, maybe you can try to use partial $apply feature.

see more https://github.com/Soontao/light-odata/blob/main/docs/API.SystemQueryOptions.md#transformations