Filter by commander's color identity

**Is your feature request related to a problem? Please describe.**
When customizing my commander deck, I always specify filters that combine color identity conditions, just like in the attached image. Is there any way to make this easier?

When the color identity is black and red:

**Describe the solution you'd like**
For example,
1, Create a filter for "cards that can be included within the commander's color identity."
2, Set the color filter to evaluate based on the "commander's color identity."

Start by locating the existing card color filter and the code that provides a commander's color identity. Trace how combined color conditions are evaluated, then define the filter behavior for cards allowed by that identity and for color filters based on it. Done means both requested filtering modes work for the black-and-red example and have coverage in the relevant existing tests.

Written by the indexing model from the issue text.