[QRE] Dollar cost calculator

[Dima Fedoriaka (fedimser)]

• Added abstract class DollarCostModel that represent a mathematical function that takes resource physical estimates (number of qubits and runtime) and returns dollar cost.
  • The plan is to add this to Target in the future.
• Added dataclass CostSpec which serves as JSON schema for JSON files that can be used to describe cost specification of a quantum computer.
• Added class DollarCostModelFromSpec that implements DollarCostModel using cost spec loaded from JSON file.
• Added method EstimationTable.add_cost_column that computes dollar cost for every entry in the table:
  • You can pass arbitrary DollarCostModel there using keyword cost_model.
  • Or you can pass cost_spec which must be path to JSON file using schema specified by CostSpec.
• Added an example JSON spec and notebook using EstimationTable.add_cost_column.
• Added optional (for QRE only) dependency on dataclasses-json, for automatic conversion from JSON to CostSpec dataclass.
• Example: https://github.com/microsoft/qdk/blob/17d2462362108d4df96f98a3863110ff2a69e3e2/samples/qre/dollar_cost.ipynb

[Mathias Soeken (msoeken)]

Is it worth to add an extra dependency? How would the code change if you don't add this dependency?