554b064214
The layer parenting did not account for storing an initial parent inverse matrix (to "keep transform"). This adds this matrix, stores it in DNA, and uses it when we compute the parent matrices on demand. Note: This PR does not set the parent inverse matrix outside of conversion from GPv2. Support for "keep transform" parenting will have to be added in another PR. Pull Request: https://projects.blender.org/blender/blender/pulls/120462