Avoid SystemStackError on project eager loading wrapper

[ulferts]

Ticket

https://community.openproject.org/wp/63498

What are you trying to accomplish?

Avoid SystemStackError when fetching a larger list of projects via the API v3. The problem arises when having 1000 projects in the system (could also happen sooner) and fetching those via the API by specifying pageSize=1000.

For all of the projects, the ancestors are prefetched for efficient rendering in the representer.

Before, this was done by constructing an AREL object that had a structure like this:

Grouping
  OR
    Grouping
      OR

So a grouping and an OR was added for every project to the statement.

This crashed but using a similar approach with AR does not seem to be affected by the same problem. This was tested for 2000 projects which ran through without problems.