feat: update dotted statements, make nodes more descriptive

[hkimura-intersys]

Key Changes:

1. Keyword naming -- the keywords within the legacy version of statements is labeled with _old to make it easy to query these statements to refactor them.
2. Made the dot within dotted statements an actual node -- this is helpful for querying/refactoring.
3. Fixed dotted statements edge case

Dotted Statements Edge Case

There was an edge case, that was caused really by a scanner error, that made it so rather than producing a termination, the dots in a dotted statement were eaten. This error was found in this example:

i x = 2 d  d okay set x = 2
 . set x = 1.2
 . set y = 1.2
 . w !,"goodbye" d
 . . new x
 . . set x = 250
 . . w !, x 
 . . quit
 . quit

The scanner has been adjusted, and this issue is now resolved with this PR.