PagesCreated: add countsOnly option

[agoujot]

(It took me a laughably long time to figure out that I needed to add a line to XtoolsController to be able to add an option to a child controller.)

Bug: T229581

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 71.21%. Comparing base (4b8eb28) to head (d8e3eba).
⚠️ Report is 162 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #550      +/-   ##
============================================
- Coverage     71.30%   71.21%   -0.10%     
- Complexity     1275     1296      +21     
============================================
  Files            46       46              
  Lines          3792     3908     +116     
============================================
+ Hits           2704     2783      +79     
- Misses         1088     1125      +37     

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