attic: remove all files which required EclipseGridParser

since the attic is the place for bits to rot silently, I doubt that
this code would have been of much contemporary use anyway. Even if it
could be made to compile, porting it to opm-parser would hardly be
worth the effort. If you are nostalgic and want to see how things were
done in the olden days, use `git show $COMMIT` or `git log --stat` or
`git log -p` and search for "EclipseGridParser"...
remove the EclipseGridParser class

RIP!
rename all "newParserDeck" objects to "deck"

The "new" parser is now "the" parser...
remove the `table_t` type

that was an artifact only required for the old parser