OpenSystemsDevelopment / qpdf

Eliminate the use of shared pointers in JSONParser

libjpeg development files are on the macos GitHub Actions build image
now, and downloading our own version was causing conflicts.

Reduce boilerplate and increase efficiency by avoiding setting and
branching on action and ready in getToken.

Also, reject them in strings.

Handle all incomplete token type errors in tokenError.

(except '\\' and '\uXXXX')

Reflect that the ls_number case only handles the digits after an 'e'.

Also, change state to ls_number for all 'ready' numbers.

Also, allow 'E' as alternative to 'e'.

Also. remove '.' as  starting char in lsTop.