Use more appropriate scopes instead of keyword.other

[wise0704]

Original comment: #277 (comment)

• Expression word operators should also take either keyword.operator.wordlike.* (C++) or keyword.operator.expression.* (TypeScript).
  All of these are currently keyword.other.*
  • await
  • default
  • nameof
  • typeof
  • as (keyword.operator.cast.as.cs might be the best fit)
  • with
  • new (keyword.operator.new.cs might be good enough, still better than keyword.other.)
  • stackalloc
  • using (using directive)
  • using static (using directive)
• Definition keywords keyword.other.* → storage.type.*
  • class
  • interface
  • delegate
  • enum
  • struct
  • record
  • namespace
  • event
  • operator
  • var
  • get
  • set
  • init
  • add
  • remove
  • extern alias
• Modifiers keyword.other.* → storage.modifier.*
  • implicit
  • explicit
• Block control keywords keyword.other.* → keyword.control.*
  • checked
  • unchecked
  • lock
  • using (using statement)
  • where
  • (not yet added) fixed
  • (not yet added) unsafe