Add IB Tiered Fee Model

[LouisSzeto]

Description

• Add IB Tiered Fee Structure Model
• Refactor the current IB fee model implementation
• Add Crypto support

Related Issue

Motivation and Context

Missing feature

Requires Documentation Change

Add to Writing Algorithms / Reality Modeling / Transaction Fee / Supported Models

How Has This Been Tested?

• Unit tests
• Regression tests

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [X] Refactor (non-breaking change which improves implementation)
• [ ] Performance (non-breaking change which improves performance. Please add associated performance test and results)
• [X] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Non-functional change (xml comments/documentation/etc)

Checklist:

• [X] My code follows the code style of this project.
• [X] I have read the CONTRIBUTING document.
• [X] I have added tests to cover my changes.
• [X] All new and existing tests passed.
• [X] My branch follows the naming convention bug-<issue#>-<description> or feature-<issue#>-<description>

[slorion]

Thanks for this addition, I just happen to need it too 👍

IBKR mentions that "Orders where the commission cap is applied do not count towards the monthly volume tiers." (footnote 7) I do not see this part handled in the code?

[slorion]

I'm also looking into Alpaca broker and I see that regulatory fees for equities are not modeled, but they would be the same as IBKR. It's outside the scope of this PR, but worth keeping in mind that it is also needed when trading USA equities with other brokers.

[ianfiske]

This hasn't moved in a few months -- is there a plan to merge this MR?