Add ability to select "counts.blocks" in bugzilla query output table

[mb]

Documented in https://bmo.readthedocs.io/en/latest/api/core/v1/bug.html#:~:text=counts

"counts.blocked" doesn't work, likely due to the dot. ("filed_via" does work, that has the same documented requirement of also including _extra).

Example:

<bugzilla>
{
    "whiteboard": "[mediawiki-bugzilla]",
    "include_fields": ["id", "summary", "whiteboard", "status", "resolution", "counts.blocked"]
}
</bugzilla>