Add some more tests for iterator filters

[jppelteret]

Fixes #13169

[jppelteret]

@simonsticko Can you check if this works for you?

[jppelteret]

/rebuild

[bangerth]

You currently have this error in a number of places:

/jenkins/workspace/dealii_PR-13170/tests/grid/filtered_iterator_07_operator.cc:55:26: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
   Assert(n_cells_visited == Utilities::fixed_power<dim>(2),
                          ^

(Also line 99, and in the corresponding test without _operator in the name.)

[simonsticko]

@simonsticko Can you check if this works for you?

Yes, works for me. 👍

[jppelteret]

Yes, works for me.

Great, thanks for the confirmation.

You currently have this error in a number of places:

Thanks for the heads up. I've changed the counter type from unsigned int to int.