OpenSystemsDevelopment / qpdf

* Make it a runtime error, not a logic error
* Include additional information
* Capture it properly in checkLinearization

* Handle error conditions that occur when using the object handle
  interfaces. In the past, some exceptions were not correctly
  converted to errors or warnings.
* Add more detailed information to qpdf-c.h
* Make it possible to work more explicitly with uninitialized objects

It was exercised in the pdf-linearize example but not in qpdf-ctest.

Thanks for the nudge from m-holger!

The impact on the code would be extremely high, and using it would
clutter the code greatly because it would break chaining like
a.getKey("/B").getKey("/C"). There are better ways to deal with the
issue.

Return new qpdf_oh from qpdf_oh_wrap_in_array when input is already an array.
Update some doc comments in qpdf-c.h.

Fix typo in --rotate example

Don't assume endobj is at the beginning of the line. This means we are
looking at tokens for every line, but the odds of n n obj appearing in
the middle of the object are likely much lower than endobj not being
at the beginning of the line or missing entirely. This will probably
have a negative impact on recovery time for very large files.
Hopefully it will be worth it.

Main branch is `main` now

Thanks @neuhaus!