Divider - removed isVertical prop

[evwilkin]

Follow up to breaking change PR patternfly/patternfly-react#8199

We removed the deprecated isVertical boolean prop from the Divider component. We should create a codemod to remove this prop from consumers' code, replace it as needed with the orientation prop which accepts an object of values at different breakpoints.

Required actions:

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