Revamp tokens and add import / export support

[TIny-Hacker]

Info

It would be a significant improvement to add import / export support to the extension, and no longer require the additional step of copying and pasting from SC3 or TI-Connect CE. Most likely would be done using tivars_lib_cpp.

Tasks

• Research way to make the feature fit in well with VS Code - use command palette.
• Change highlighting to match the token syntax here as opposed to SC3's
• Import / export TI-BASIC programs

[TIny-Hacker]

Importing seems to work, but it's a little slow and could still be improved somewhat. I'll look into exporting next.

[TIny-Hacker]

Importing and exporting works properly now. However, I'm waiting to push till:

• Correct indentation
• Use tivars_lib_cpp with ASCII
• Return certain unicode

[TIny-Hacker]

I still need to do some testing but otherwise the feature is good to go as of 97a7cab.