Feature Request: Support for OData Function $apply with Aggregations and GroupBy

[hotLutzi]

Description:

I would like to propose a new feature for the Automapper.Extensions.OData library that adds support for the OData function $apply. Currently, the library supports a variety of OData functions, but it lacks the capability to handle aggregations and groupby, which are essential for many applications.

Motivation:

The $apply function is a central part of OData, allowing for efficient data processing through aggregations and groupings. This functionality is particularly important for applications managing and analyzing large datasets. Without this support, developers are forced to seek alternative solutions that may not integrate as seamlessly into the existing infrastructure.

Expected Behavior:

• Implementation of the $apply function that supports aggregations (e.g., count, sum, average) and groupby operations.
• Ensure backward compatibility with the existing functionalities of the library.

I believe that this enhancement would significantly improve the functionality of Automapper.Extensions.OData and enrich the user experience for developers working with OData.

Use Cases:

1. Analyzing numeric data with aggregations to determine average values.
2. Grouping user information to create reports on user residential data.
3. Grouping E&I data to show items from the same series

I look forward to feedback and hope that this feature can be implemented in a future release. Thank you for your work on this library!

Example

Microsoft Documentation of Grouping and Aggregation

[BlaiseD]

ok - to submit a PR.

[ramiabughazaleh]

There was some work started in PR #108 but it wasn't completed.