Merge the PPD* classes that were used by the DOM preprocessor with the
hash preprocessor classes that extend them. This resolves many issues
with types/phpcs and it removes unused code left over from the DOM
preprocessor.
Bug: T278069
Bug: T204945
Change-Id: I4b160b4610e5c7ba47e9e31db252cc00d2e345df
And also update approximated counts, which for the most part are lower
than reported (hooray!)
Bug: T231636
Depends-On: Ica50297ec7c71a81ba2204f9763499da925067bd
Change-Id: I78354bf5f0c831108c8f606e50c87cf6bc00d8bd