New feature: type-to-type conversion

[markjoshwel]

• example 1: from string query

  $ s+ Ngee Ann Polytechnic --convert-to pluscode
  surplus version 2.0.0
  6PH58QMF+CW

  $ s+ Ngee Ann Polytechnic --convert-to localcode
  surplus version 2.0.0
  8QMF+CW Singapore

  $ s+ Ngee Ann Polytechnic --convert-to latlong
  surplus version 2.0.0
  1.333562, 103.774812

• example 2: from latlong coord

  $ s+ 1.333562, 103.774812 --convert-to pluscode
  surplus version 2.0.0
  6PH58QMF+CW

  $ s+ 1.333562, 103.774812 --convert-to localcode
  surplus version 2.0.0
  8QMF+CW Singapore

  # if parsed type matches, dont do any calulations, just return
  $ s+ 1.333562, 103.774812 --convert-to latlong
  surplus version 2.0.0
  1.333562, 103.774812

  $ s+ 1.333562, 103.774812 --convert-to text
  Ngee Ann Polytechnic
  535 Clementi Road
  Bukit Timah
  599489
  Northwest, Singapore

hilariously, any non-string-to-string conversion is just running surplus()

[markjoshwel]

undertaking this might be sizeable, so i might delay it for 2.1.0

however, as i am currently working on 2.0.0 i'll develop with this in mind so that i don't have to botch my way around and into fresh code

[markjoshwel]

map of what to do

surplus conversions

pluscode
    --> pluscode    --> (return __str__ of querytype)
    --> localcode   --> ???
    --> latlong --> (return Latlong.__str__)
    --> sharetext   --> (normal pre-2.1 surplus operation)
localcode
    --> pluscode    --> PlusCodeQueryType.to_full_length(...)
    --> localcode   --> (return __str__ of querytype)
    --> latlong --> (return Latlong.__str__)
    --> sharetext   --> (normal pre-2.1 surplus operation)
latlong
    --> pluscode    --> (use PlusCodes lib)
    --> localcode   --> ???
    --> latlong --> (return __str__ of querytype)
    --> sharetext   --> (normal pre-2.1 surplus operation)
querystring
    --> pluscode    --> (get latlong, then use PlusCodes lib)
    --> localcode   --> ???
    --> latlong --> (return Latlong.__str__)
    --> sharetext   --> (normal pre-2.1 surplus operation)