Feature: add MaxPages option to project queries

[madhonk1208]

Currently the maximum of pages that will be traversed is set to a static value.

const PageNumberLimit = 2

But for bigger projects and especially bigger teams, the traversal fetch of just two pages is not enough. For example if you want to calculate the velocity of the last 10 sprints in project x that contains y repositories, contributing z team members.

So I added in the query options of projects a MaxPages traversal option. This option replaces the static PageNumberLimit in projects.

In fact the user that created the query is in charge how many pages should be fetched.

If there are less pages available, the already existing code will break the loop.

Default value is set to 2
Max value is limited to 30

Sad that at the moment github projectsV2 does not support more features like sorting and filtering. Hopefully this code will be obsolete in future releases of github graphql.

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