[FEATURE] Enable queries using "root" and "-1" for pidInList

The version preview in the frontend rendering process basically
selects only the live versions and then overlays those records
with possible versions. Since the MM handling is changed to
directly point to the most specific version in that regard (this
is an exception to the "always live, overlay then" approach), the
versions also need to be selected directly. ContentObjectRenderer
uses the method PageRepository::enableFields() which adds an
additional SQL WHERE part, like " AND tablename.pid<>-1" to
exclude possible versions.

Besides that, elements (like sys_catagory) that are stored on the
root-level cannot be queried at all which leads to custom code in
the end just to perform these queries.

This change allows selections on the root-level and disables the
"pid<>-1" constraint if the opposite has been defined in the
pidInList property.

Example:
select.pidInList = root,-1

Resolves: #57168
Documentation: #57171
Releases: 6.2
Change-Id: I6fb91f89f70614d59c83d808f07e890833248880