Banner - replaced variant prop with color

[thatblindgeye]

Follow up to breaking change PR patternfly/patternfly-react#9891

We should update the variant prop to color, unless the variant was default in which case we should remove the prop. The error message should also mention something along the lines of "if you used the variant prop for color, use color prop, otherwise use status prop if you were using variant to convey status" or something.

Required actions:

1. Build codemod
2. Build test
3. Update readme with description & example