Improve content assist - phase 2

Improve content assist processor to provide better/more relevant suggestions

Use cases for proposing:

• fields/functions of structured types after a variable/constant/function call etc. + "."
  • union, record, set
  • component
  • class
  • function without parameters
  • function with parameters
  • function parameters
• component operations, e.g. MyComp.create/done/stop etc.
• port operations, e.g. MyPort.start/stop/send/receive etc.
• timer operations, e.g. MyTimer.start/stop/read/running/timeout
• all/any timer/component/port operations
• testcases after 'execute('
• verdicts after 'setverdict('
• in doc comments, 'deprecated' after '@status'
• encoding related proposals
  • encoding types
  • encoding attributes
  • attribute keyword
  • attribute modifier
  • extension attribute keywords
  • extension attribute prototype settings
  • extension attribute printing settings
  • extension attribute encode/decode type
  • extension attribute encode/decode option
• after class 'extends' propose potential base classes considering the following:
  • don't propose the class itself
  • don't propose classes that are already listed in the 'extends' list
  • if a non-trait class is already listed, only propose trait classes
  • don't propose final classes that cannot be extended
• modifier keywords starts with "@"
  • class definition: type class @abstract/@final/@trait
  • class function definition: function @final/@abstract/@deterministic
  • module function definition: function @control/@deterministic
  • function parameter: function (@modifier)? fname(..., @lazy/@fuzzy