Implement DEFER then Refactor

[mitra42]

DEFER is a Forth2012 concept that replaces user variables like 'NUMBER

[mitra42]

• [x] DEFER - has sample implementation DEFER
  • since would like to use it early, this means as a IMMEDIATE JS code word with a token
  • for efficiency
  • • has sample implementation
• [x] DEFER@ - has sample implementation
• [x] DEFER! - has sample implementation
• [x] IS - has state-dependent sample implementation
• [x] ACTION-OF - has state-dependent sample implementation
• [x] >BODY needs extending to understand structures built with DEFER
• [x] Edit places that functionality of DEFER is currently used e.g. 'NUMBER
• [x] Edit places where words are redefined unneccessarily e.g. to use new version of TICK