Add draft profit calculator for a user

[ikripaka]

Describe the feature

Add a draft calculator to review possible strategies for using the Options trading tool. This involves introducing a calculator that estimates the possible profit that can be made after a successful combination of expiry and exercise.

[zahorodnyi]

I plan to extend the browse and positions commands so they also show the current profit for user, according to the current BTC price and option terms.

[zahorodnyi]

About the browse extension:
We don’t know which part of the contract a taker wants to take, so we can’t display the current profit for his future part of the contract. However, I think it would be useful to show it for some common percentages, such as 100% or 10%, wouldn’t it? If so, which percentages should be shown?

[zahorodnyi]

About the positions extension:

1. First of all, we have to find and show active options in a separate table - where some taker has already taken a part - and also show in this table:

• role (maker/taker),
• status (grantor or option token),
• active part of option (already taken, for the maker),
• user part (for the taker),
• user's current profit (user’s current profit for his active part)
• current BTC price
  and maybe something else...