OpenSystemsDevelopment / qpdf

 Add new Buffer method copy and deprecate copy constructor / assignment operator

Future

Also fix accidental Buffer copy in Pl_LZWDecoder::addToTable.

Also remove trailing whitespace

Bump minimum clang-format version to 16

 Change JSONHandler::m to std::unique_ptr and declare Members in implementation file

Also enforce in format-code.

Apply various Clang-Tidy rules

Remove redundant loop in QPDFWriter::prepareFileForWrite

Avoid unnecessary copying of stream dictionary in QPDF::readObject

Code tidy - reflow comments and strings

Rename README-maintainer to README-maintainer.md and add table of content

Remove lgtm.yml

lgtm was discontinued in 2022.

Add .git-blame-ignore-revs file

Code tidy - reflow comments and strings