Consistently use palloc_object() and palloc_array()

Hi hackers,

I've changed all code to use the "new" palloc_object(), palloc_array(),
palloc0_object(), palloc0_array, repalloc_array() and repalloc0_array()
macros. This makes the code more readable and more consistent.

The patch is pretty big but potential merge conflicts should be easy to
resolve. If preferred, I can also further split up the patch, e.g.
directory by directory or high impact files first.

The patch is passing "meson test" and I've additionally wrote a script
that parses the patch file and verifies that every two corresponding +
and - lines match (e.g. palloc0() replaced by palloc0_array() or
palloc0_object(), the same for palloc() and repalloc(), additionally
some checks to make sure the conversion to the _array() variant is
correct).

--
David Geier