fix: plan was not determined correctly for virtual migration

[iamsauravsharma]

• fix: children parents where not determined correctly when virtual migration was used in replaces list
• fix: while generating migration list related to app name, migration name, related migration list where not correct if there is virtual migration in function call for run before or parent
• test: add tests for testing different virtual migration case instead of only testing non virtual migration
• test: not only test if plan is ok or err but also test plan have correct list and correct error