Text-on-path mirrored in layer with mirroring transform (e.g. from pdf import)

Migrated from: https://bugs.launchpad.net/inkscape/+bug/1806066

Steps to reproduce:

• open test.svg file
• observe that the text-on-path is upside-down The file was originally created by importing a pdf
• create a new layer (above or below)
• select the path and text and moving it to the new layer causes the text path to flip (the text remains upside down) (see test2.svg)
• the "fix" for this issue of copying the text and pasting it into a new layer does not work on Inkscape 1.0

Comment on original bug: "I can confirm this... For pdf imports, somehow, there is a mirroring of layers."

Inkscape Version and Operating System:

• Inkscape Version: 1.0alpha (d7d7b92)
• Operating System: Windows 10
• Operating System version: 1803