PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/tools/notes/CONTRIBUTING.md#commit-messages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• You have signed the CLA.
• All existing tests are passing: https://github.com/NativeScript/NativeScript/blob/master/tools/notes/DevelopmentWorkflow.md#running-unit-tests-application.
• Tests for the changes are included - https://github.com/NativeScript/NativeScript/blob/master/tools/notes/WritingUnitTests.md.

What is the current behavior?

During iOS rotation layout, some views end up with misaligned background/borders. That is because computation updates native view frame at a certain point and appends safe-area insets.
I attached screenshots from a yellow view with a bottom border.

Before screen rotation:

After screen rotation:

What is the new behavior?

Layout procedure will mark size as changed in case frame has been updated to include safe-area insets.
This PR also includes some cleanup regarding position types.