created advanced contract task type

[Ugo-X]

closes #265

• [x] Add the calls optional field to the QuestTaskDocument type in src\models.rs if it is not already present. This is an array of Call. Each Call is an object with the following fields: contract (string), call_data (string array), entry_point (string), regex (string). If it doesn't already exist, I suggest you to create a Call type that you can then use to type the Calls field.
  • [x] Reuse the code from the verify_balance route.
  • [x] After each call, check the output using the regex field corresponding to field.

[Marchand-Nicolas]

Also there are several errors in verify_contract due to non existing import. You can implement the missing types

[Ugo-X]

Just fixed those chief. its funny cos i already did it all in one go but apparently my auto save was turned off and i didnt notice it .... hahaha